JP6478617B2 - Brake device - Google Patents

Description

  The present invention relates to a brake device that applies a braking force to a vehicle.

  A brake device configured to apply braking force to a vehicle such as an automobile by supplying a brake fluid pressure corresponding to an operation amount of a brake pedal toward a brake mechanism (wheel cylinder) on each wheel side. Is installed. A brake mechanism typified by a disc brake, for example, supplies a hydraulic pressure from the outside into a cylinder of a caliper, so that the piston is brought together with a brake pad (ie, a braking member) on the surface side of the disc (ie, a braked member) To generate a braking force.

  Such a brake device not only generates a braking force based on the hydraulic pressure when the vehicle is traveling, but also operates as a parking brake when the vehicle is parked or parked. There is known a brake device with an electric parking brake function that moves linearly (that is, moves in the axial direction) to come into contact with the piston and generates a braking force by the movement of the piston at this time (for example, Patent Documents). 1).

JP2013-209041A

  Here, Patent Document 1 does not consider at all the case where the clearance between the piston and the linear motion member is increased to the extent that the response at the next parking brake operation is affected by the wear of the brake pad.

  Accordingly, an object of the present invention is to provide a brake device that can perform a clearance adjustment operation by an electric parking brake.

  In order to solve the above-described problem, a brake device according to the present invention includes a braking member that applies a braking force to a vehicle by pressing a braked member that rotates with a wheel, and the braking member is directed toward the braked member, or A piston that moves in a direction away from the member to be braked, a linear member that moves linearly by driving an electric motor and moves the piston in contact with the piston, and an application for applying a braking force to the vehicle And a control unit that performs release control for releasing the braking force of the vehicle, and the control unit starts calculating the travel distance at the timing when the release control is performed, and depends on the travel of the vehicle Travel distance calculation means for calculating distance data, and distance data determination means for determining whether the distance data calculated by the travel distance calculation means is normal And when the distance data is determined to be abnormal by the distance data determination means and the vehicle has traveled, regardless of the distance data of the travel distance calculation means, And an abnormal time control means for controlling the linear motion member to contact the piston.

  ADVANTAGE OF THE INVENTION According to this invention, the brake device which enabled adjustment operation of the clearance by an electric parking brake can be provided.

The conceptual diagram of the vehicle carrying the brake device by embodiment. The control block diagram which shows the parking brake control apparatus etc. in FIG. The longitudinal cross-sectional view which expands and shows the disc brake with an electric parking brake function provided in the rear-wheel side. The flowchart which shows the determination process of the automatic adjustment control by a parking brake control apparatus. The flowchart which actualizes and shows the odometer value abnormality determination process in FIG. The flowchart which actualizes and shows the travel distance calculation process after the release in FIG. FIG. 5 is a flowchart showing the auto adjustment control process in FIG. 4 in detail. The time chart which shows the relationship of parking brake apply, release control, odometer value, travel distance, etc. when the odometer value is normal. The time chart which shows relationships, such as parking brake apply, release control, odometer value, and travel distance, in the first case where the odometer value becomes abnormal. The time chart which shows the relationship of the parking brake apply, release control, odometer value, travel distance, etc. in the second case where the odometer value becomes abnormal. The time chart which shows relationships, such as parking brake apply, release control, odometer value, and travel distance, in the third case where the odometer value becomes abnormal.

  Hereinafter, a case where the brake device according to the embodiment is mounted on a four-wheeled vehicle will be described as an example and described with reference to the accompanying drawings. Each step of the flowcharts shown in FIGS. 4 to 7 uses the notation “S”, and for example, step 1 is indicated as “S1”.

  In FIG. 1, on the lower side of a vehicle body 1 constituting the vehicle body, for example, a total of four left and right front wheels 2 (FL, FR) and left and right rear wheels 3 (RL, RR). Wheels are provided. The front wheel 2 and the rear wheel 3 are provided with a disc rotor 4 as a braked member that rotates together with the respective wheels (each front wheel 2 and each rear wheel 3). The disc rotor 4 for the front wheel 2 is given a braking force by a hydraulic disc brake 5, and the disc rotor 4 for the rear wheel 3 is given a braking force by a hydraulic disc brake 21 with an electric parking brake function. The Thereby, each wheel (front wheel 2 and rear wheel 3) is independently applied with braking force or released from braking.

  A brake pedal 6 is provided on the front board side of the vehicle body 1. The brake pedal 6 is depressed by the driver when the vehicle is braked. By this operation, the disc brakes 5 and 21 are applied with braking force as service brakes and are released. The brake pedal 6 is provided with a brake lamp switch, a pedal switch, a brake operation detection sensor 6A (also referred to as a pedal stroke sensor or a brake sensor), and the like. The brake operation detection sensor 6A detects whether or not the brake pedal 6 is depressed, or the operation amount thereof, and outputs a detection signal to a control unit (C / U 13) described later.

  When the driver of the vehicle depresses the brake pedal 6, the operating force (input) is transmitted to the master cylinder 8 while being boosted by the booster 7. The booster 7 is configured as a negative pressure booster or an electric booster provided between the brake pedal 6 and the master cylinder 8, and increases the pedal force when the brake pedal 6 is depressed and transmits it to the master cylinder 8. At this time, the master cylinder 8 that functions as a hydraulic pressure source generates a hydraulic pressure by the brake fluid supplied from the master reservoir 9. The master reservoir 9 is composed of a hydraulic fluid tank that stores brake fluid. The mechanism for generating the hydraulic pressure by the brake pedal 6 is not limited to the above configuration, and a mechanism for generating the hydraulic pressure in response to the operation of the brake pedal 6, for example, a brake-by-wire mechanism or the like may be used.

  The hydraulic pressure generated in the master cylinder 8 is sent to a hydraulic pressure supply device 11 (hereinafter referred to as ESC 11) via, for example, a pair of cylinder side hydraulic pipes 10A and 10B. The ESC 11 is a device that is disposed between the disc brakes 5 and 21 and the master cylinder 8 and distributes and supplies the hydraulic pressure from the master cylinder 8 to the disc brakes 5 and 21. That is, the hydraulic pressure from the master cylinder 8 is distributed and supplied to the respective disc brakes 5 and 21 via the brake side piping portions 12A, 12B, 12C, and 12D by the ESC 11. Thereby, a braking force is independently applied to each of the wheels (each front wheel 2 and each rear wheel 3).

  Here, the ESC 11 has a dedicated control device configured by, for example, a microcomputer, that is, a control unit 13 (hereinafter referred to as C / U 13). The C / U 13 opens and closes each control valve (not shown) of the ESC 11 and performs drive control to rotate and stop an electric motor (not shown) for the hydraulic pump, thereby Control is performed to increase, decrease, or maintain the brake fluid pressure supplied to the disc brakes 5 and 21 from the pipe portions 12A to 12D independently of each other. Thereby, various brake controls (for example, boost control, braking force distribution control, brake assist control, antilock brake control, traction control, vehicle stabilization control including skid prevention, slope start assist control, etc.) are executed. .

  The C / U 13 is supplied with power from the battery 14 through the power supply line 15. The C / U 13 is connected to the vehicle data bus 16. A known ABS unit or the like can be used instead of the ESC 11. Furthermore, it is possible to omit without providing the ESC 11, and in such a case, a mechanical hydraulic pressure control valve or the like is provided between the master cylinder 8 and the brake side piping portions 12A to 12D. That's fine.

  The vehicle data bus 16 includes a CAN (Controller Area Network) as a serial communication unit mounted on the vehicle body 1, and is connected to a large number of electronic devices mounted on the vehicle, the C / U 13, the parking brake control device 18, and the like. It is a data bus for performing multiplex communication within a vehicle. Vehicle information sent to the vehicle data bus 16 includes, for example, an ignition switch (IGN SW), a seat belt sensor, a door lock sensor, a door open sensor, a seating sensor, a vehicle speed sensor, in addition to a detection signal from the brake operation detection sensor 6A. , Steering angle sensor, accelerator operation sensor, throttle sensor, engine rotation sensor, brake fluid pressure sensor, gradient sensor, shift sensor, acceleration sensor, wheel speed sensor, pitch sensor for detecting movement in the vehicle pitch direction (all Vehicle information based on a detection signal from an unillustrated) or the like.

  The vehicle body 1 is equipped with an odometer (not shown) that is an integrated odometer of the vehicle. Then, the odometer value (distance data corresponding to the travel distance of the vehicle) measured by the odometer is sent to the vehicle data bus 16 in such a manner that it is sequentially updated when the vehicle travels. The parking brake control device 18 as a control unit reads such an odometer value from the vehicle data bus 16 and can store it in the storage device 20 described later as necessary.

  In the vehicle body 1, a parking brake switch 17 (PKB SW shown in FIG. 2) is provided in the vicinity of a driver's seat (not shown), and the parking brake switch 17 is operated by the driver. The parking brake switch 17 transmits a signal corresponding to a parking brake operation request (apply request, release request) from the driver to a parking brake control device 18 as a control unit. That is, the parking brake switch 17 outputs a signal (apply request signal, release request signal) for applying or releasing the brake pad 23 based on the rotational drive of the electric motor 37 to the parking brake control device 18. To do.

  As shown in FIG. 2, the parking brake control device 18 has an input side connected to a vehicle data bus 16, a parking brake switch 17, a current sensor (not shown), etc., and an output side a disc brake 21 with an electric parking brake function. It is connected to the. The current sensor detects a current value flowing through the electric motor 37 and outputs a detection signal (for example, a signal for detecting a load state of the electric motor 37) to the parking brake control device 18. In addition to the central processing unit 18A (that is, the CPU 18A), the parking brake control device 18 includes a drive circuit 19 as a motor driver that drives an electric motor 37 of the disc brake 21 described later, and data necessary for controlling the parking brake. And a storage device 20 for storing information.

  The storage device 20 is composed of memory components such as a flash memory, a ROM, a RAM, and an EEPROM. The storage device 20 includes an automatic adjustment control determination processing program shown in FIG. 4, a threshold Ls for determining the travel distance L, and conditions (a) to (g) described later for performing the automatic adjustment control. ), The odometer value abnormality determination processing program shown in FIG. 5, the post-release travel distance calculation processing program shown in FIG. 6, and the auto-adjustment control processing shown in FIG. A program and a history flag of an odometer abnormality traveling history shown in FIG. 5 to be described later are stored.

  S2 of the processing procedure shown in FIG. 4 is for performing a travel distance calculation process after release (see FIG. 6), and shows a specific example of travel distance calculation means for calculating distance data based on the travel of the vehicle. Further, in the odometer value abnormality determination process shown in FIG. 5, the determination process in S11 is whether or not the odometer value read from the vehicle data bus 16 is abnormal (for example, abnormal due to disconnection of CAN, etc.), that is, the odometer value. Distance data determination means for determining whether the distance data calculated by the travel distance calculation means is normal or abnormal based on the above.

  Further, when the distance data is determined to be abnormal by the distance data determination means and the vehicle has traveled, the linear motion member when the vehicle is stopped in an unlocked state regardless of the distance data of the travel distance calculation means The abnormal time control means for controlling 35 to contact the piston 29 includes S3 and S4 in the processing procedure shown in FIG. This abnormal time control means is the case where the history flag is set to “present” when the odometer abnormal time running history is set as described later by the odometer value abnormality determination processing of FIG. 5 and other conditions (b) of the automatic adjustment control. When (g) is satisfied, auto-adjustment control is performed.

  On the other hand, the processing by S3 and S4 in FIG. 4 includes a specific example of the normal time control means. The normal time control means is a case where a travel distance L described later is equal to or greater than a threshold value Ls (L ≧ Ls) while the distance data is determined to be normal by the distance data determination means, and the automatic adjustment control is performed. When other conditions (b) to (g) are satisfied, automatic adjustment control is performed.

  When the parking brake switch 17 is turned on to the braking side by the driver, an apply request signal is output from the parking brake switch 17. At this time, the parking brake control device 18 outputs (feeds) electric power for rotating the electric motor 37 to the braking side from the drive circuit 19 to the disc brake 21 for the rear wheel 3. Thereby, the disc brake 21 for the rear wheel 3 is in a state where a braking force as a parking brake is applied (that is, an applied state).

  On the other hand, when the parking brake switch 17 is turned off by the driver to release the braking, a release request signal is output from the parking brake switch 17. At this time, the electric power for rotating the electric motor 37 in the direction opposite to the braking side is supplied to the disc brake 21 for the rear wheel 3 via the parking brake control device 18. As a result, the disc brake 21 is in a state where the application of the braking force as a parking brake is released (ie, in the released state).

  Next, the configuration of the disc brake 21 provided on the left and right rear wheels 3 will be described with reference to FIG. In FIG. 3, only one of the left and right disc brakes 21 provided on the left and right rear wheels 3 is shown as a representative example.

  Here, the disc brake 21 for the rear wheel 3 is configured as a hydraulic disc brake provided with an electric parking brake function. The disc brake 21 constitutes a brake device (brake system) together with the parking brake control device 18 which is a control unit. The disc brake 21 includes a mounting member 22 attached to a non-rotating portion on the rear wheel 3 side of the vehicle, an inner side and outer side brake pad 23 as a braking member (friction pad), and a brake provided with an electric actuator 36. It includes a caliper 24 as a mechanism.

  In this case, the disc brake 21 pushes the brake pad 23 against the disc rotor 4 by propelling the piston 29 in the cylinder portion 26 of the caliper body 25 by the hydraulic pressure based on the operation of the brake pedal 6 or the like, and the wheel (rear) A braking force is applied to the wheel 3). Further, the disc brake 21 for the rear wheel 3 is also operated in response to an operation request from the parking brake control device 18 based on a signal from the parking brake switch 17 or the like. At this time, the disc brake 21 propels the piston 29 through the rotation / linear motion conversion mechanism 33 by an electric actuator 36 (electric motor 37) described later, and presses the brake pad 23 against the disc rotor 4 to thereby move the wheel (rear wheel). Apply braking force to 3).

  The mounting member 22 includes a pair of arms (not shown) extending in the axial direction of the disk rotor 4 (ie, the disk axial direction) so as to straddle the outer periphery of the disk rotor 4 and spaced apart from each other in the disk circumferential direction. A thick-walled support portion 22A that is fixed to a non-rotating portion of the vehicle at a position on the inner side of the disc rotor 4, And a reinforcing beam 22B for connecting the distal end sides of the arm portions to each other.

  The inner and outer brake pads 23 are disposed so as to be in contact with both surfaces of the disk rotor 4 and are supported by the respective arm portions of the mounting member 22 so as to be movable in the disk axial direction. The brake pads 23 on the inner side and the outer side are pressed against both sides of the disc rotor 4 by calipers 24 (the claw portions 28 and the pistons 29 of the caliper main body 25). As a result, each brake pad 23 sandwiches (presses) the disk rotor 4 that rotates together with the wheel (rear wheel 3) from both sides to apply braking force to the vehicle.

  A caliper 24 as a wheel cylinder is disposed on the mounting member 22 so as to straddle the outer peripheral side of the disk rotor 4. The caliper 24 is provided so as to be slidably inserted into the caliper body 25 supported by each arm portion of the mounting member 22 so as to be movable along the axial direction of the disk rotor 4. The piston 29, a rotation / linear motion conversion mechanism 33, an electric actuator 36, and the like, which will be described later, are provided. The caliper 24 operates the piston 29 by the hydraulic pressure generated in the master cylinder 8 based on the operation of the brake pedal 6. At this time, the piston 29 is moved together with the brake pad 23 toward the disk rotor 4 or in a direction away from the disk rotor 4.

  The caliper body 25 includes an inner cylinder portion 26, a bridge portion 27, and an outer claw portion 28. The inner cylinder portion 26 is formed in a bottomed cylindrical shape in which one side in the axial direction is closed by the partition wall portion 26 </ b> A and the other side in the axial direction facing the disk rotor 4 is opened. The bridge portion 27 is formed to extend from the cylinder portion 26 in the disk axial direction so as to straddle the outer peripheral side of the disk rotor 4. The outer side claw portion 28 is disposed so as to extend radially inward from the bridge portion 27 on the side opposite to the cylinder portion 26.

  The hydraulic pressure associated with the depression operation of the brake pedal 6 or the like is supplied into the cylinder portion 26 (that is, a hydraulic pressure chamber 30 described later) of the caliper body 25 via the brake side piping portion 12C or 12D shown in FIG. . A partition wall portion 26 </ b> A is integrally formed in the cylinder portion 26 so as to be positioned between the back side (one side in the axial direction) and the electric actuator 36. The partition wall portion 26A of the cylinder portion 26 has a through hole 26B in the axial direction, and an output shaft 36B of an electric actuator 36 described later is rotatably inserted inside the through hole 26B.

  A bottomed cup-shaped piston 29 having a bottom portion 29A and a cylindrical portion 29B is inserted into the cylinder portion 26 of the caliper body 25 so as to be slidable in the axial direction. The bottom portion 29A of the piston 29 is formed on the inner side. It faces the brake pad 23. A hydraulic chamber 30 is defined between the partition wall portion 26 </ b> A of the cylinder portion 26 and the piston 29, and the hydraulic chamber 30 is sealed by a piston seal 31. The hydraulic pressure from the master cylinder 8 is supplied into the hydraulic pressure chamber 30 via a supply / discharge port (not shown) provided in the cylinder portion 26. A dust boot 32 is interposed between the outer peripheral surface of the bottom portion 29 </ b> A of the piston 29 and the opening-side inner peripheral surface of the cylinder portion 26 in order to prevent foreign matter from entering the cylinder portion 26.

  Between the cylinder portion 26 of the caliper body 25 and the piston 29, a rotation / linear motion conversion mechanism 33 is provided in the hydraulic pressure chamber 30. The rotation / linear motion conversion mechanism 33 converts rotational motion by an electric actuator 36 described later, that is, rotation of the electric motor 37 into linear motion (hereinafter referred to as linear motion), and applies axial thrust to the piston 29. In addition, it has a function of holding the piston 29 at the braking position. As shown in FIG. 3, the rotation / linear motion conversion mechanism 33 is configured to be accommodated in the piston 29, but it is sufficient that the piston 29 is propelled by the rotation / linear motion conversion mechanism 33. The dynamic conversion mechanism 33 does not necessarily need to be accommodated in the piston 29.

  The rotation / linear motion conversion mechanism 33 includes a screw member 34 formed of a rod-like body formed with a male screw such as a trapezoidal screw, and a linear motion member 35 serving as a propulsion member having a female screw hole formed of a trapezoidal screw formed on the inner peripheral side. It is configured. That is, the screw member 34 screwed to the inner peripheral side of the linear motion member 35 constitutes a screw mechanism that converts a rotational motion by an electric actuator 36 described later into a linear motion of the linear motion member 35. In this case, the female screw of the linear motion member 35 and the male screw of the screw member 34 are formed using highly irreversible screws (for example, trapezoidal screws).

  As a result, the rotation / linear motion conversion mechanism 33 causes the frictional force (holding force) to move the linear motion member 35 (that is, the piston 29) at an arbitrary position even when power supply to the electric actuator 36 (that is, the electric motor 37) is stopped. The energy can be saved by stopping the power feeding. The rotation / linear motion conversion mechanism 33 only needs to be able to hold the piston 29 at a position propelled by the electric actuator 36. For example, a highly irreversible triangular screw other than a trapezoidal screw or a worm gear is used. May be configured.

  The screw member 34 screwed to the inner peripheral side of the linear motion member 35 is provided with a flange portion 34A that is a large-diameter flange on one side in the axial direction, and the other side in the axial direction is the bottom of the piston 29. It extends toward the 29A side. The screw member 34 is integrally connected to an output shaft 36B of an electric actuator 36 described later on the flange portion 34A side. Further, on the outer peripheral side of the linear motion member 35, there is provided an engagement protrusion 35A that stops the linear motion member 35 with respect to the piston 29 (regulates relative rotation) and allows relative movement in the axial direction. In the linear motion member 35, the distal end portion 35B on the other side in the axial direction abuts against the bottom 29A side of the piston 29, and pushes the piston 29 in the axial direction to propel it.

  The electric actuator 36 constitutes a parking brake actuator and has a casing 36A that forms an outer shell thereof. The casing 36 </ b> A of the electric actuator 36 is fixed to the cylinder portion 26 at an outer position of the partition wall portion 26 </ b> A (that is, a position on one side in the axial direction of the cylinder portion 26 of the caliper body 25). The electric actuator 36 includes an electric motor 37 composed of a stator and a rotor (not shown) provided in the casing 36A, and a speed reducer (shown in the figure) that is disposed in the casing 36A and decelerates the rotation of the electric motor 37 to increase torque. (Not shown).

  Furthermore, the electric actuator 36 has an output shaft 36 </ b> B that outputs the rotational torque from the speed reducer to the rotation / linear motion conversion mechanism 33. An output shaft 36B of the electric actuator 36 extends along the partition wall portion 26A of the cylinder portion 26 along the through hole 26B, and is connected to rotate integrally with the flange portion 34A side of the screw member 34 in the cylinder portion 26. The connecting means between the screw member 34 and the output shaft 36B can be configured to be movable in the axial direction, for example, but not to rotate in the rotational direction. In this case, a known technique such as spline fitting or fitting with a polygonal column (non-circular fitting) is used.

  The speed reducer provided in the casing 36A of the electric actuator 36 may be configured using, for example, a gear type speed reduction mechanism represented by a planetary gear speed reducer or a worm gear speed reducer. When a known speed reducer having no reverse operation (irreversible) such as a worm gear speed reducer is used, the rotation / linear motion converting mechanism 33 is a known reversible known function such as a ball screw or a ball and ramp mechanism. A mechanism can be used.

  Here, when the driver operates the parking brake switch 17 shown in FIGS. 1 to 3 to the braking side, electric power is supplied to the electric motor 37 of the electric actuator 36 via the parking brake control device 18, and the electric actuator 36. The output shaft 36B is rotationally driven. For this reason, the screw member 34 of the rotation / linear motion converting mechanism 33 is rotated integrally with the output shaft 36 </ b> B in one direction, for example, and propels (drives) the piston 29 toward the disk rotor 4 via the linear motion member 35. Accordingly, the disc brake 21 is in a state where the disc rotor 4 is sandwiched between the inner side and outer side brake pads 23 and a braking force is applied as an electric parking brake, that is, a holding state (applied state).

  On the other hand, when the parking brake switch 17 is operated to the brake release side, the screw member 34 of the rotation / linear motion conversion mechanism 33 is rotationally driven in the other direction (reverse direction) by the electric actuator 36. As a result, the piston 29 and the linear motion member 35 are driven in a retreating direction away from (separated from) the disc rotor 4, and the disc brake 21 is released from the braking force as a parking brake, that is, in a released state (release state). )

  In this case, the rotation of the linear motion member 35 of the rotational linear motion conversion mechanism 33 within the piston 29 is restricted by the engagement protrusion 35A. For this reason, when the screw member 34 is relatively rotated with respect to the linear motion member 35, the linear motion member 35 is relatively moved in the axial direction according to the rotation angle of the screw member 34. That is, the rotation / linear motion conversion mechanism 33 converts the rotational motion of the screw member 34 into the linear motion of the linear motion member 35, and the tip portion 35 </ b> B of the linear motion member 35 propels the piston 29 in the axial direction. Further, the rotation / linear motion converting mechanism 33 can hold the linear motion member 35 at an arbitrary position by the frictional force. As a result, the piston 29 and the brake pad 23 are held at the positions propelled by the electric actuator 36.

  A thrust bearing 38 is provided between the partition wall portion 26 </ b> A of the cylinder portion 26 and the flange portion 34 </ b> A of the screw member 34. The thrust bearing 38 receives the thrust load from the screw member 34 together with the partition wall portion 26A, and makes the screw member 34 rotate smoothly with respect to the partition wall portion 26A. The partition wall portion 26A of the cylinder portion 26 is provided with a seal member 39 between the partition wall portion 26A and the output shaft 36B of the electric actuator 36. The seal member 39 causes brake fluid in the cylinder portion 26 to leak to the electric actuator 36 side. It seals between the two to prevent it.

  The disc brake 5 on the front wheel 2 side has substantially the same configuration except for the disc brake 21 on the rear wheel 3 side and the parking brake mechanism. That is, unlike the disc brake 21 on the rear wheel 3 side, the disc brake 5 on the front wheel 2 side is not provided with the rotation / linear motion conversion mechanism 33 and the electric actuator 36 that operate (hold and release) the parking brake. . However, in other respects, the disc brake 5 on the front wheel 2 side is configured in substantially the same manner as the disc brake 21 on the rear wheel 3 side. In some cases, a disc brake 21 with an electric parking brake function may be provided on the front wheel 2 side in place of the disc brake 5.

  The brake device for a four-wheeled vehicle according to the present embodiment has the above-described configuration. Next, the operation thereof will be described.

  When the driver of the vehicle depresses the brake pedal 6, the pedaling force is transmitted to the master cylinder 8 via the booster 7, and brake fluid pressure is generated by the master cylinder 8. The hydraulic pressure generated in the master cylinder 8 is distributed and supplied to the disc brakes 5 and 21 via the cylinder side hydraulic pipes 10A and 10B, the ESC 11 and the brake side pipes 12A, 12B, 12C and 12D, and left and right. Braking force is applied to the front wheel 2 and the left and right rear wheels 3 respectively.

  In this case, the disc brake 21 on the rear wheel 3 side will be described. When the hydraulic pressure is supplied into the cylinder portion 26 of the caliper 24 via the brake-side piping portions 12C and 12D, the hydraulic pressure in the cylinder portion 26 increases. The piston 29 slides and displaces toward the brake pad 23 on the inner side. As a result, the piston 29 presses the inner brake pad 23 against one side surface of the disk rotor 4, and the entire caliper 24 against the respective arm portions of the mounting member 22 by the reaction force at this time. Sliding displacement to the side.

  As shown in FIG. 3, in the caliper 24 of the disc brake 21, when the hydraulic pressure is supplied to the hydraulic chamber 30 of the cylinder portion 26, the piston 29 causes the piston seal 31 to elastically deform and the initial position during non-braking. The inner brake pad 23 is pressed against the disc rotor 4 by moving forward (moving rightward in FIG. 3). The caliper body 25 moves to the left in FIG. 3 with respect to the attachment member 22 by the pressing reaction force of the piston 29, and pushes the outer brake pad 23 abutting on the claw portion 28 against the disc rotor 4. wear. As a result, the disc rotor 4 is sandwiched between the pair of brake pads 23, and a braking force is generated in the vehicle by the frictional force at this time.

  Next, when the driver releases (releases) the operation of the brake pedal 6, the hydraulic pressure supply from the master cylinder 8 is cut off, so that the caliper 24 side of the disc brake 21 is in the hydraulic chamber 30 of the cylinder portion 26. Fluid pressure decreases. Accordingly, the piston 29 is retracted to the initial position in the cylinder portion 26 by the restoring force of the elastic deformation of the piston seal 31 and the braking force is released. Note that when the amount of movement of the piston 29 increases as the inner and outer brake pads 23 wear, and the elastic deformation limit of the piston seal 31 is exceeded, slippage occurs between the piston 29 and the piston seal 31. Arise. By this slip, the initial position of the piston 29 with respect to the cylinder portion 26 of the caliper body 25 moves.

  As a result, the pad clearance is adjusted to be substantially constant even when the brake pad 23 is worn. However, when the initial position of the piston 29 is moved due to pad wear, the rotation / linear motion conversion mechanism 33 for parking brake (that is, the tip 35B of the linear motion member 35) and the bottom 29A of the piston 29 are As shown in FIG. 3, a clearance C is generated, and this clearance C may become larger than necessary according to pad wear. For this reason, in the present embodiment, automatic adjustment control is performed according to the processing procedure shown in FIGS. 4 to 7 described later to suppress the clearance C from becoming excessive.

  Next, when the driver of the vehicle operates the parking brake switch 17 to the braking side (on), power is supplied from the parking brake control device 18 to the electric motor 37 of the disc brake 21, and the output shaft 36B of the electric actuator 36 is Driven by rotation. The disc brake 21 with an electric parking brake function converts the rotation of the electric actuator 36 into linear motion via the screw member 34 and the linear motion member 35 of the rotation / linear motion conversion mechanism 33, and moves the linear motion member 35 in the axial direction. Then, by propelling the piston 29, the pair of brake pads 23 are pressed against both surfaces of the disk rotor 4.

  At this time, the linear motion member 35 is held in a braking state by a frictional force (holding force) generated between the screw member 34 and the disc brake 21 on the rear wheel 3 side is operated (applied) as a parking brake. That is, even after the power supply to the electric actuator 36 is stopped, the linear motion member 35 (that is, the piston 29) can be held at the braking position by the female screw of the linear motion member 35 and the male screw of the screw member 34.

  In other words, the parking brake control device 18 determines the pressing force applied to the disc rotor 4 from the pair of inner-side and outer-side brake pads 23 to a predetermined value (for example, an application supplied to the electric motor 37). The electric motor 37 is driven until the current driving current reaches a predetermined current value. The driving current at this time is detected by the current sensor. Thereafter, when the parking brake control device 18 detects that the pressing force to the disc rotor 4 has reached a predetermined value (specifically, the drive current of the electric motor 37 is a predetermined value), the parking brake control device 18 energizes the electric motor 37. Stop. Thereby, the screw member 34 stops rotating in the apply direction, and accordingly, the axial displacement (linear motion) of the linear motion member 35 is also stopped.

  At this time, a pressing reaction force from the disk rotor 4 acts on the linear motion member 35. However, a rotational resistance torque that opposes the pressing reaction force is generated between the male screw of the screw member 34 and the female screw of the linear motion member 35. That is, the screw fitting portion between the two has a great irreversibility and does not reversely operate. For this reason, the screw member 34 of the rotation / linear motion converting mechanism 33 is maintained in a stopped state without rotating, and the piston 29 can be held at an intended braking position. As a result, the braking force is maintained and the operation as a parking brake is continued. In this state, the pressing reaction force from the disk rotor 4 is transmitted to the partition wall portion 26 </ b> A of the cylinder portion 26 via the linear motion member 35, the screw member 34, and the thrust bearing 38, and the parking brake holding force against the piston 29. give.

  Next, when releasing (releasing) the parking brake, the parking brake switch 17 is turned OFF, so that the parking brake control device 18 returns the piston 29 (that is, the piston 29 is separated from the disk rotor 4). The electric motor 37 is rotationally driven in the release direction). As a result, the electric actuator 36 decelerates the electric motor 37 with the speed reducer and transmits the rotation of the required torque to the screw member 34, and the screw member 34 is in a direction opposite to the direction of application (release direction for returning the piston 29). Rotating drive.

  At this time, the pressing reaction force from the disk rotor 4 acts on the screw member 34 via the linear motion member 35. Thereby, a rotational resistance torque acts on the screw fitting portion between the male screw of the screw member 34 and the female screw of the linear motion member 35. The rotational torque in the release direction transmitted from the electric actuator 36 (electric motor 37) is transmitted to the screw member 34 and also to the female screw of the linear motion member 35. Thereby, the linear motion member 35 moves to the partition wall portion 26A side (release direction) of the cylinder portion 26 and returns to the initial position in the axial direction. The screwing position of the male screw of the screw member 34 and the female screw of the linear motion member 35 returns to the initial position, and the rotation of the screw member 34 in the release direction is stopped.

  Then, the parking brake control device 18 rotates the electric motor 37 at the time when the distance between the tip 35B of the linear motion member 35 and the bottom 29A of the piston 29 reaches an initial position having a predetermined clearance C (gap). Control to stop. At this time, the piston 29 is retracted to the initial position by the restoring force of the elastic deformation of the piston seal 31 and the braking force is completely released. Thus, the disc brake 21 releases the holding force to the piston 29 by returning the linear motion member 35 of the rotation / linear motion conversion mechanism 33 to the initial position when the parking brake is released.

  By the way, this kind of brake device drives a piston by hydraulic pressure by a brake operation during vehicle travel, and pushes a brake pad (braking member) to the surface side of a disk (braking member) to make friction contact. For this reason, the brake member gradually wears every time the brake operation is performed, and accordingly, the piston moves relative to the linear motion member in the preceding direction. As described above, when the braking member is worn due to the braking operation during vehicle travel, a large clearance is generated between the piston and the linear motion member. And if it is going to operate an electric parking brake in such a state, since it is necessary to drive a linear motion member by an electric motor so that it may move greatly by the clearance, the responsiveness at the time of parking brake operation falls. In addition, the braking performance of the vehicle may be reduced.

  Therefore, brake pad wear is estimated based on the distance traveled since the last release of the electric parking brake (that is, travel distance after release control), and the amount of wear affects the responsiveness at the next activation. When it is determined that the electric motor is affected, it is conceivable that the electric motor is automatically driven to rotate so as to adjust the clearance between the internal part (linear motion member) of the electric parking brake and the piston.

  However, when the travel distance of the vehicle is acquired by an external system such as an odometer, if an abnormality occurs in the acquired information, the travel distance cannot be calculated, and therefore the wear amount of the brake pad cannot be estimated. For this reason, even when the clearance between the piston and the linear motion member due to wear of the brake pad is enlarged so as to affect the responsiveness at the next parking brake operation, the clearance is not automatically adjusted. There is a fear.

  Specifically, when the brake pad 23 is worn due to a brake operation during vehicle travel, the clearance C (see FIG. 3) between the piston 29 and the linear motion member 35 increases more than necessary. If the electric parking brake is to be operated in such a state (clearance C is excessive), the electric actuator 36 adds an extra rotation / linear motion conversion mechanism 33 to move the linear motion member 35 by the clearance C. Therefore, not only the responsiveness when the parking brake is actuated but also the braking performance of the vehicle may be lowered.

  Further, when the travel distance (for example, odometer value) of the vehicle is acquired from the vehicle data bus 16 by CAN communication, if an abnormality occurs in the acquired information, the travel distance cannot be calculated. As a result, the brake pad 23 The amount of wear cannot be estimated. In this case, the parking brake control device 18 determines whether or not the clearance C between the piston 29 and the linear motion member 35 due to wear of the brake pad 23 has increased so as to affect the response at the next parking brake operation. It cannot be judged.

  Therefore, in the present embodiment, in order to solve such a problem, the determination process of the automatic adjustment control by the parking brake control device 18 is performed according to the processing procedure shown in FIGS.

  When the process shown in FIG. 4 starts, an odometer value abnormality determination process is executed in S1 according to the procedure shown in FIG. In S2, the travel distance calculation process after release is executed according to the procedure shown in FIG. In next S3, it is determined whether or not conditions (a) to (g) described later are satisfied. If it is determined as “YES” in S3, it can be determined that the auto-adjustment control can be executed. Therefore, the process proceeds to the next S4 to perform an auto-adjustment control process (a control process according to FIG. 7 described later). On the other hand, while “NO” is determined in S3, the automatic adjustment control is not performed, the process returns in the next S5, and the processes in and after step 1 are repeated. Of the processing procedure shown in FIG. 4, S3 and S4 constitute a specific example of the abnormal time control means or the normal time control means according to the present invention.

  Next, the odometer value abnormality determination processing in S1 will be described with reference to FIG. When the process starts, it is determined whether or not the odometer value is abnormal in S11. When the odometer value (that is, the mileage of the vehicle) is acquired from the vehicle data bus 16 by CAN communication, for example, if the odometer value cannot be acquired due to disconnection of the CAN, the odometer value becomes abnormal and “YES” in S11 Is determined. On the other hand, when the odometer value is normally acquired, it is determined as S11 “NO”. In the next S12, a history flag “none” is set as an odometer abnormality running history, and the process returns in the next S13.

  If "YES" is determined in S11, it is determined whether or not the vehicle is traveling in the next S14. For example, when the state where the wheel speed is 2 km / h or more continues for a predetermined time (for example, 30 milliseconds), it is determined that the vehicle is traveling. If “YES” is determined in S14, the vehicle is traveling in a state where the odometer value has become abnormal. Therefore, in the next S15, the history flag is set as “Odometer abnormal traveling history” and the next flag is set. The process returns at S13.

  On the other hand, while it is determined as “NO” in S14, it can be determined that the vehicle is not running and is stopped. Therefore, in the next S16, it is determined whether or not the release completion timing when the parking brake is released. judge. This may be determined from a change in the current value by the current sensor, or may be determined from a signal from the parking brake switch 17. And while determining “NO” in S16, it can be determined that the parking brake has been released (released) or is in a state before release (for example, during operation of the parking brake). .

  Therefore, in the next S17, the running history at the time of odometer abnormality is the same as the previous time, that is, without changing the history flag, and the process returns in the next S13. Note that the odometer abnormality travel history can be initialized by setting the odometer abnormality travel history “none” and the history flag at the stage where the odometer value abnormality determination process of FIG. 5 is first started (for example, when the engine is started). That's fine. However, after the history flag is set to “Yes” in S15, even when the vehicle is stopped, as long as “NO” is determined in S16, the odometer abnormality travel history in S17. Continue to set the history flag to “Yes” as before.

  On the other hand, when it is determined as “YES” in S16, it can be determined, for example, that the parking brake switch 17 is turned OFF and the release completion timing (that is, the parking brake is released) is reached. In other words, it can be determined that the clearance C (see FIG. 3) between the piston 29 and the linear motion member 35 is set to an appropriate gap size at this timing. Therefore, in the next S18, an odometer abnormality travel history “none” and a history flag are set, and the next S13 returns.

  Next, the post-release travel distance calculation process (that is, the travel distance calculation means) in S2 will be specifically described with reference to FIG. When the process starts, it is determined whether or not it is a release completion timing at which the parking brake is released in S21. This may be determined from the change in the current value as described above, or may be determined from a signal from the parking brake switch 17. For example, when the parking brake switch 17 is turned off, “YES” is determined in S21, so that the process proceeds to the next S22 and the vehicle travel distance (odometer value at the time of release) is read from the vehicle data bus 16, Is stored as the initial value L1.

  On the other hand, if “NO” is determined in S21, the vehicle is in the state after the parking brake is released (released) or before the release (for example, during the operation of the parking brake). The travel distance (current odometer value) of the vehicle is read from the data bus 16 and stored as an update value Lx. In next S24, the travel distance L (that is, distance data) of the vehicle after releasing the parking brake is calculated as a difference between the update value Lx and the initial value L1, as shown in the following equation (1).

The travel distance L from the timing at which the parking brake is finally released (release control) is calculated by the above equation 1 even when the system is temporarily restored even if the system is temporarily down due to insufficient power of the battery or the like. It is necessary to continue the calculation of the travel distance L. Therefore, the initial value L1 can be stored in the storage device 20 of the parking brake control device 18 even when the system is down. Note that the calculation result of the travel distance L may be stored.

Next, the determination process of S3 shown in FIG. 4 will be specifically described. That is, in S3, it is determined whether or not the following conditions (a) to (g) are satisfied.
(A) Whether the history flag is “Obtained” when the odometer is abnormal, or whether the travel distance L after release is greater than or equal to the threshold Ls. (B) The vehicle is stopped (c) The electric parking brake is released (released) (D) The ignition switch (IGN SW) changes from ON to OFF. (E) The actuator of the electric parking brake is not operating. (F) The input data used for auto adjustment control is normal. (G) The operation request of other actuators. There is no

  That is, if it is determined that the conditions (a) to (g) are satisfied in S3 and “YES” is determined, it can be determined that the auto-adjustment control can be executed, so the process proceeds to the next S4 and the auto-adjustment control process ( The control process according to FIG. 7 described later is performed. On the other hand, while “NO” is determined in S3, the automatic adjustment control is not performed, the process returns in the next S5, and the processes in and after step 1 are repeated.

  Here, the condition (a) described above indicates that the odometer value cannot be acquired due to, for example, CAN disconnection, the odometer value is abnormal (or fixed to a specific value), and the history flag is “Odometer Abnormal Travel History” Or a condition for determining whether or not the wear amount of the brake pad 23 has increased beyond a predetermined amount.

  The threshold value Ls for the travel distance L after release (that is, distance data) is set to 1000 km, for example. This threshold value Ls is a travel distance that assumes a case where the brake pad 23 is highly likely to be worn out, such as sudden braking from high speed travel, and in some cases, the travel distance is 1000 km or more. It is also possible to set. In other words, the travel distance of the threshold value Ls is larger when the pad is worn (that is, the clearance C between the piston 29 and the linear motion member 35 is larger than the time required to complete the normal operation after the parking brake switch 17 is turned ON. ) Is set to a predetermined value (travel distance) such that the operation completion delay time is within one second.

  The condition (b) is a condition for detecting that the vehicle is stopped. The parking brake control device 18 determines whether or not the vehicle is stopped based on the wheel speed information acquired from the vehicle data bus 16. For example, when the state where the wheel speed is less than 1 km / h continues for a predetermined time (for example, 30 milliseconds) or more, it is determined that the vehicle is stopped, and the state for 2 km / h or more continues for the predetermined time (also 30 milliseconds) or more. It is determined that the vehicle is traveling. When performing auto-adjustment control, it is necessary to drive the electric actuator 36 once in the apply direction, and thrust is generated at that time. Therefore, if auto-adjustment control is performed during traveling, a braking force unintended by the driver may be generated, which may affect vehicle behavior. In order to avoid such influence, the auto-adjustment control can be executed only when the vehicle is stopped.

  Condition (c) is a condition for detecting that the parking brake is released. In the auto-adjustment control, the electric actuator 36 is driven in the apply direction, and then the electric actuator 36 is driven in the release direction. For this reason, if auto-adjustment control is performed while the parking brake is operating, the parking brake is inadvertently released, and the vehicle may slide down a slope or the like. In order to avoid such a problem, the auto-adjustment control can be executed only in the release (release) state.

  The condition (d) is a condition for determining the vehicle driver's intention to park. Since thrust is generated when the parking brake is applied (actuated), the auto-adjustment control needs to be executed at a timing that does not hinder (do not obstruct) the driver's intention to start. Therefore, in the present embodiment, when the ignition switch (IGN SW) is turned off, it is confirmed that the driver does not intend to start (that is, the parking intention), and the execution timing of the auto adjustment control is determined on this. It may be determined by monitoring that the vehicle engine is stopped.

  Condition (e) is a condition for determining whether or not the electric motor 37 is stopped. If the electric motor 37 is being driven in the apply direction, the parking brake is in an operation complete state when the electric motor 37 stops, and the internal parts (for example, the linear motion member 35) of the electric parking brake are moved to the piston 29. Abut. That is, since there is no clearance C to be adjusted between the piston 29 and the linear motion member 35, automatic adjustment control is unnecessary. On the other hand, when the electric motor 37 is driven in the release direction, when the electric motor 37 is stopped, the release completion state (that is, a state in which an appropriate clearance C is secured) is obtained, so that auto adjustment control is not necessary. . Accordingly, when the electric motor 37 is driven to the operating side or the release side, in any case, if the electric motor 37 stops, the auto-adjustment control becomes unnecessary. Therefore, it is confirmed that the electric motor 37 is not operating.

  The condition (f) is a condition for determining whether or not the input data (input signal) is correct in order to prevent the automatic adjustment control from being erroneously executed. For example, when the wheel speed information by the vehicle data bus 16 is abnormal, it cannot be determined whether or not the vehicle is running. If auto-adjustment control is executed at this time, an unintended braking force may occur during traveling. In order to avoid such a situation, when the input data (excluding input data such as an odometer value used for calculating the travel distance) is abnormal, the automatic adjustment control is prohibited.

  Furthermore, the condition (g) is a condition for determining whether another request is generated by the driver's SW operation or the like at the auto adjustment execution timing. Since the auto-adjustment control is an auxiliary function for maintaining the operation performance of the parking brake, it is necessary to prioritize the driver's request when other requests from the driver are detected at the auto-adjustment execution timing. For this reason, it is confirmed that there is no request for operation of other actuators.

  When the above conditions (a) to (g) are satisfied, the parking brake control device 18 executes auto-adjustment control according to the processing procedure shown in FIG. First, in S31, it is determined whether or not the operation control of the electric motor 37 in the auto adjustment control is incomplete (that is, whether or not the apply direction driving is complete).

  When it determines with "YES" by S31, it moves to following S32 and drives the electric motor 37 to an apply direction. Then, the process returns at the next S33, and the processes after S31 are continued. If “NO” is determined in S31, the drive in the apply direction has been completed, so the process proceeds to the next S34 to determine whether or not the release direction control of the electric motor 37 has not been completed (that is, the release direction drive has been completed). Whether or not). If it is determined “YES” in S34, the electric motor 37 is driven in the release direction. Thereby, the clearance C (gap in the axial direction) between the piston 29 and the linear motion member 35 is appropriately adjusted.

  Here, whether or not the operation control has been completed by the process of S31 (that is, the drive in the apply direction of the electric motor 37 is not completed) is a change in the current value flowing through the electric motor 37 (the current detected by the current sensor). Value). In the automatic adjustment control, it is not necessary to generate thrust as in normal apply control, and the internal part of the parking brake (that is, the linear motion member 35) can be moved to a position where it contacts (contacts) the piston 29. It is enough. For this reason, compared with the time of normal apply control, the threshold value (not shown) of the current for determining the completion of the apply can be set low.

  As an example, when it is determined that the normal apply control is completed when the value of the current flowing through the electric motor 37 reaches 10 A, the current value flowing through the electric motor 37 is the current value of the idle running section in the auto adjustment control. In contrast, it can be determined that the operation control has been completed when it has increased by 0.5 A. However, in the present embodiment, the automatic adjustment control is performed after confirming the driver's intention to park in advance, and since the automatic adjustment control is performed in the parking / stopping state of the vehicle, the same current as in the normal apply control is used. It is also possible to use a threshold value.

  In next step S34, it is determined whether or not the release control (drive in the release direction) of the electric motor 37 in the automatic adjustment control is incomplete. Also in this case, it can be determined from the change in the value of the current flowing through the electric motor 37 whether or not the driving of the electric motor 37 in the release direction has been completed. When it is determined as “NO” in S34, the drive in the release direction of the electric motor 37 has been completed, so that the process proceeds to the next S33 and returns. As described above, the release (release) control is performed in the same manner as the normal release control in order to ensure the same clearance C as the normal release control.

  Thus, according to the present embodiment, the parking brake control device 18 estimates the degree of wear (amount of wear) of the brake pad 23 based on the travel distance L as the distance data acquired from the vehicle data bus 16. When the travel distance L from the timing when the parking brake is finally released (released) becomes equal to or greater than a predetermined threshold value Ls (for example, 1000 km), the wear of each brake pad 23 causes the piston 29 and the linear motion member 35 to move. The clearance C is large, and it is expected that the response of the apply control will deteriorate when the driver tries to operate the parking brake next time.

  Therefore, in order to avoid problems at the time of the next parking brake operation (for example, a decrease in responsiveness at the time of parking brake operation, a decrease in the braking performance of the vehicle, etc.), the determination process at S3 in FIG. It is determined whether or not the travel distance L from the timing when the control is performed is equal to or greater than the threshold value Ls, and whether or not the other conditions (b) to (g) of the automatic adjustment control are satisfied.

  As a result, the vehicle is stopped, the ignition switch (IGN SW) is turned OFF, and the auto-adjustment control is executed according to the processing procedure shown in FIG. 7 in the non-braking state where the vehicle is not locked. As a result, the auto-adjustment control can be performed only when it is determined that the brake pad 23 is worn purely by the service brake. Thereby, the execution frequency of auto-adjustment control can be suppressed to the minimum necessary as compared with the prior art, and the load applied to the electric parking brake (disc brake 21) can be reduced.

  On the other hand, for example, if the odometer value cannot be acquired due to disconnection of CAN or the like, the odometer value becomes abnormal (see S11 in FIG. 5). In this case, the calculation of the travel distance L (that is, the calculation of the distance data) by the equation 1 cannot be performed properly, and the wear amount of the brake pad 23 cannot be estimated. For this reason, even when the clearance C (see FIG. 3) between the piston 29 and the linear motion member 35 is enlarged so as to affect the responsiveness at the time of the next parking brake operation due to wear of the brake pad 23, the auto adjustment is performed. Control will not be performed.

  Therefore, in the present embodiment, when the distance data determining means determines that the distance data is abnormal (that is, the odometer value is abnormal in S11 of FIG. 5) and the vehicle travels, the distance data of the travel distance calculating means is included in the distance data. Regardless, there is provided an abnormality control means for controlling the linear motion member 35 to come into contact with the piston 29 when the vehicle is in an unlocked state and stopped. This abnormal time control means is configured to include S3 and S4 shown in FIG. 4, and when the history flag is set to “present” when the odometer abnormal traveling history is present, and other conditions of auto adjustment control ( When b) to (g) are satisfied, automatic adjustment control (that is, automatic clearance adjustment operation) is performed.

  As a result, even if the odometer value cannot be acquired due to the disconnection of the CAN and the odometer value becomes abnormal and the travel distance cannot be calculated (that is, the distance data cannot be calculated), the piston 29 and the linear motion member 35 are not connected. Auto-adjustment control can be executed before the clearance C is expanded to the extent that the responsiveness at the time of the next parking brake operation is affected by the wear of the brake pad 23, and the next time the parking brake is applied (applied). Responsiveness can be maintained.

  The time chart shown in FIG. 8 shows the operation of the ignition switch (IGN SW) when the distance data based on the odometer value is normal (that is, when the distance data determination means determines that the distance data is normal), the application of the electric parking brake, The relationship between the release control, the driving state of the vehicle, the odometer value, the travel distance after release, and the travel history when the odometer is abnormal is expressed as time series data. In this case, the electric parking brake is switched from the activated (applied) state to the released (released) state at time Ta1, so that the travel distance after release is reset to zero.

  Thereafter, when the vehicle travels (drives) from time Ta2, the travel distance after the release is integrated as the odometer value increases. When a vehicle that is traveling (driving) is stopped at the next time Ta3, the travel distance L after release (that is, distance data) exceeds a predetermined threshold value Ls. For this reason, at the time Ta4, the ignition switch (IGN SW) is switched from ON to OFF and the engine is stopped, and auto-adjustment control is performed as normal time control means when the distance data is normal.

  When the auto-adjustment control is completed at time Ta5, the travel distance after release is reset to zero again, and the electric parking brake is in the released state. Further, the travel history when the odometer is abnormal is set to “none” in the history from time Ta1 to Ta6. That is, in the odometer value abnormality determination process shown in FIG. 5, when the distance data based on the odometer value is normal, the process from S11 to S13 is repeated, and thus the history flag is held as “none” in the odometer abnormality travel history.

  Next, the time chart shown in FIG. 9 shows that the first case where the distance data based on the odometer value becomes abnormal (that is, the first case where the distance data determination means determines that the distance data is abnormal) is normal as described above. It is represented as time series data similar to FIG. Also in this case, the electric parking brake is switched from the applied state to the released state at time Tb1, so that the travel distance after the release is reset to zero. Thereafter, when the vehicle travels (drives) from time Tb2, the travel distance after release is integrated as the odometer value increases.

  However, in this case, at time Tb3, the odometer value cannot be acquired due to, for example, disconnection of the CAN, and the distance data based on the odometer value is abnormal. For this reason, for example, the odometer value is not updated over time Tb3 to Tb6, and the travel distance after the release is smaller than the threshold value Ls as shown in FIG. However, the vehicle in this case continues to travel (drive) until time Tb4, and at this time, the travel distance L after the release may actually exceed the threshold value Ls. That is, it cannot be determined whether or not the actual travel distance L exceeds the threshold value Ls, and there is a possibility that the actual travel distance L actually exceeds the threshold value Ls.

  Therefore, at the time when the vehicle driver switches the ignition switch (IGN SW) from ON to OFF at time Tb5 and stops the engine, automatic adjustment control when the distance data is abnormal is executed just in case. When auto-adjustment control is completed at time Tb6, the travel distance after release is reset to zero again, and the electric parking brake is in a released state.

  In the case of FIG. 9, the running history at the time of odometer abnormality is set to “none” until time Tb3. However, after the time Tb3, since the vehicle is traveling even if the distance data based on the odometer value becomes abnormal, the traveling history when the odometer is abnormal is set to “present” from time Tb3 to Tb6. That is, in the odometer value abnormality determination process shown in FIG. 5, if the distance data based on the odometer value is abnormal, the history flag is set to “Yes” in the odometer abnormality traveling history by the processes of S11, S14, and S15.

  And even if it moves to the process of S16, S17 of FIG. 5 after that, the driving | running | working log | history at the time of odometer abnormality is hold | maintained with "it is" similarly to the last time. However, when “YES” is determined in S16, the release completion timing is reached (for example, when the release is completed by the auto-adjustment control at time Tb5 to Tb6). Therefore, in the next S18, the history flag is switched to “none” in the odometer abnormality travel history (after time Tb6 in FIG. 9).

  Next, the time chart shown in FIG. 10 shows the second case in which the distance data based on the odometer value becomes abnormal (that is, the second case in which the distance data determination means determines that the distance data is abnormal), and FIG. It is expressed as similar time series data. Also in this case, the electric parking brake is switched from the applied state to the released state at time Tc1, so that the travel distance after the release is reset to zero. Thereafter, when the vehicle travels (drives) for a period of time Tc2 to Tc3, the travel distance after the release is integrated as the odometer value increases.

  Next, in the case of FIG. 10, for example, when the time Tc4 is reached, the odometer value cannot be acquired due to disconnection of the CAN or the like, and the distance data based on the odometer value is abnormal. However, in this case, since the vehicle has already stopped (stopped) at the stage of time Tc3, for example, the odometer value is not updated over time Tc3 to Tc5, and the travel distance after release is shown in FIG. Thus, the value is smaller than the threshold value Ls.

  That is, in the case of FIG. 10, since the vehicle stops without stopping even after the distance data based on the odometer value becomes abnormal at time Tc3, the travel history when the odometer is abnormal becomes “None”. Is set. In the meantime, in the odometer value abnormality determination process shown in FIG. 5, since “NO” is continuously determined in S14, the history flag is set by the processes in S11, S14, S16, and S17 even if the distance data based on the odometer value is abnormal. The running history at the time of odometer abnormality is set to “none”.

  For this reason, in the case of FIG. 10, even when the vehicle driver switches the ignition switch (IGN SW) from ON to OFF at time Tc5 and stops the engine, automatic adjustment control is not performed and the next vehicle travel is performed. Just wait. That is, in the second case shown in FIG. 10, it is not necessary to consider the pad wear when the vehicle is stopped in spite of the abnormality determination of the distance data, so that it is not necessary to perform the auto adjustment control.

  Next, the time chart shown in FIG. 11 shows the third case in which the distance data based on the odometer value becomes abnormal (that is, the third case in which the distance data determination means determines that the distance data is abnormal), and FIG. It is expressed as similar time series data. Also in this case, the electric parking brake is switched from the applied state to the released state at time Td1, so that the travel distance after the release is reset to zero. Thereafter, when the vehicle travels (drives) for a period of time Td2 to Td3, the travel distance after release is integrated as the odometer value increases.

  However, in the third case shown in FIG. 11, the travel distance L after release has already exceeded the threshold value Ls when the vehicle is stopped (stopped) from traveling (drive) at time Td3. For this reason, for example, even if the odometer value cannot be acquired due to disconnection of the CAN at time Td4 and the distance data due to the odometer value becomes abnormal, the ignition switch (IGN SW) is turned off from ON at time Td5 thereafter. At the stage of switching and stopping the engine, auto-adjustment control is executed in the same way as when the distance data shown in FIG. 8 is normal.

  In this case, the travel distance L after the release exceeds the threshold value Ls while the vehicle travels (drives) over time Td2 to Td3. That is, the travel distance L after release has already exceeded the threshold value Ls during the time Td2 to Td3 when the distance data is determined to be normal by the distance data determination means. For this reason, as in the normal state shown in FIG. 8, automatic adjustment control is performed as a normal time control means.

  In the case of FIG. 11, since the vehicle has stopped (stopped) after the distance data based on the odometer value becomes abnormal at time Td4, the travel history when the odometer is abnormal is set to “none”. In the meantime, in the odometer value abnormality determination process shown in FIG. 5, since “NO” is continuously determined in S14, the history flag is set by the processes of S11, S14, S16, and S17 even if the distance data based on the odometer value is abnormal. As with the previous time, the running history when the odometer is abnormal is set to “none”.

  However, in S3 shown in FIG. 4, in order to determine that the travel distance L after release exceeds the threshold Ls in the case of FIG. 11, for example, even if the distance data based on the odometer value becomes abnormal at time Td4, At the time Td5 thereafter, when the ignition switch (IGN SW) is switched from ON to OFF, auto-adjustment control is executed in the same manner as when the distance data shown in FIG. 8 is normal.

  Thereafter, when the auto-adjustment control is completed at time Td6, the travel distance after release is reset to zero again, and the electric parking brake is released. At this time, in the odometer value abnormality determination processing shown in FIG. 5, even when the distance data based on the odometer value is abnormal, the history flag is set to “none” in the odometer abnormality traveling history by the processing of S11, S14, S16, and S18. Thereafter, even if the process proceeds to S16 and S17, the travel history at the time of odometer abnormality is held as “none”.

  Therefore, in the present embodiment, the clearance C (see FIG. 3) between the piston 29 and the linear motion member 35 is caused by wear of the brake pad 23 even under the condition that the distance data based on the odometer value becomes abnormal due to disconnection of the CAN or the like. If there is a possibility that it has expanded to the extent that it will affect the responsiveness at the time of the next parking brake operation, the vehicle is stopped, the ignition switch (IGN SW) is turned OFF, and the vehicle is not locked In this state, automatic adjustment control can be performed.

  When the distance data based on the odometer value is normal, it is determined whether or not the travel distance L from the timing when the release control was last performed is equal to or greater than the threshold value Ls, and the conditions (b) to It is determined whether or not (g) is satisfied. As a result, the vehicle is stopped, the ignition switch (IGN SW) is turned OFF, and the auto-adjustment control is executed according to the processing procedure shown in FIG. 7 in the non-braking state where the vehicle is not locked.

  As a result, the auto-adjustment control can be performed only when it is determined that the brake pad 23 is worn purely by the service brake. Thus, prior to the next parking brake operation, when the response of the apply control is expected to deteriorate, the adjustment operation of the clearance C by the electric parking brake is appropriately performed by performing the auto adjustment control. Thus, it is possible to suppress an excessive increase in the operation frequency of the parking brake, and to improve durability and reliability.

  In the embodiment, the case where the travel distance L after the release is calculated based on the odometer value from the vehicle data bus 16 has been described as an example. However, the present invention is not limited to this. For example, the travel distance (distance data) after release may be calculated from the vehicle body speed and time of the vehicle. Also in this case, when the vehicle travels after it is determined that the distance data is abnormal, the vehicle is stopped in an unlocked state regardless of the distance data calculated from the vehicle body speed and time. In addition, it is possible to operate an abnormal time control means for controlling the linear motion member 35 so as to contact the piston 29.

  Moreover, in the said embodiment, the case where the rotation linear motion conversion mechanism 33 for parking brakes was comprised by the screw member 34 and the linear motion member 35 was mentioned as an example, and was demonstrated. However, the present invention is not limited to this. For example, a rotation / linear motion conversion mechanism that converts rotation of an electric motor into linear motion may be configured by a base nut, a push rod, a ball and ramp mechanism, and the like. The present invention can also be applied to various rotation / linear motion conversion mechanisms other than the above.

  Moreover, in the said embodiment, the case where the parking brake control apparatus 18 was separated from C / U13 of ESC11 was mentioned as an example, and was demonstrated. However, the present invention is not limited to this. For example, the parking brake control device 18 may be configured integrally with the C / U 13. The parking brake control device 18 controls the two disc brakes 21 on the left and right, but may be provided for each of the left and right disc brakes 21. In this case, the parking brake The control device 18 can be provided integrally with the disc brake 21.

  Further, in the above embodiment, the case where the left and right rear wheel side brakes are disc brakes 21 with an electric parking brake function has been described as an example. However, the present invention is not limited to this, and the left and right front wheel side brakes may be disc brakes with an electric parking brake function, and the brakes of all wheels (all four wheels) are constituted by disc brakes with an electric parking brake function. May be.

  Next, the invention included in the above embodiment will be described. That is, according to the present invention, while the distance data determination unit determines that the distance data is normal, the control unit includes distance data (travel distance after performing release control) of the travel distance calculation unit. The wear of the braking member is estimated on the basis of this, and when it is determined that the amount of wear affects the responsiveness at the next operation, and when the vehicle is in an unlocked state, the linear motion member contacts the piston. Normal-time control means is provided for controlling the operation. Thus, under normal distance data, the distance traveled from the last release, not the distance traveled from when the parking brake was last applied, is calculated, and the clearance distance is calculated according to the distance traveled. Automatic adjustment (automatic adjustment) can be performed, and the braking performance of the vehicle can be improved. Therefore, since the auto-adjustment control can be performed only when it is determined that the pad is worn purely by the service brake, the frequency of the auto-adjustment can be suppressed to the minimum necessary, and the load applied to the electric parking brake is reduced. It becomes possible.

  Further, the control unit is configured to adjust the clearance between the piston and the linear motion member by driving the electric motor when controlling the linear motion member to contact the piston. As a result, when the driver tries to activate the parking brake next time, the response of the apply control is expected to deteriorate, and when the vehicle is in the unlocked state, the linear motion member is The automatic adjustment of the clearance can be executed so as to contact the piston, and the braking performance of the vehicle can be improved. Also, the clearance can be automatically adjusted even when the distance data when the vehicle travels is abnormal.

1 Car body 2 Front wheel
3 Rear wheels
4 Disc rotor (braking member)
6 Brake pedal 16 Vehicle data bus 17 Parking brake switch 18 Parking brake control device (control unit)
19 Drive circuit (motor driver)
20 Storage device 21 Disc brake (parking brake)
23 Brake pads (braking members)
24 caliper 26 cylinder portion 29 piston 30 hydraulic chamber 33 rotation / linear motion conversion mechanism 34 screw member 35 linear motion member 36 electric actuator 37 electric motor

Claims (3)

A braking member that applies braking force to the vehicle by pressing a braked member that rotates together with the wheels;
A piston for moving the braking member toward the braked member or in a direction away from the braked member;
A linear motion member that moves linearly by driving an electric motor and moves the piston in contact with the piston;
A control unit that performs an apply control for applying a braking force to the vehicle, and a release control for releasing the braking force of the vehicle,
The controller is
Mileage calculating means for starting calculation of mileage at the timing when the release control is performed and calculating distance data by traveling of the vehicle;
Distance data determination means for determining whether the distance data calculated by the travel distance calculation means is normal;
When the distance data is determined to be abnormal by the distance data determination means and the vehicle has traveled, the vehicle is in an unlocked state and is stopped regardless of the distance data of the travel distance calculation means. And a brake control device for controlling the linear motion member to contact the piston.   The control unit estimates wear of the braking member based on the distance data of the travel distance calculation unit while the distance data is determined to be normal by the distance data determination unit, and the wear amount is determined at the next operation. 2. The control device according to claim 1, further comprising a normal-time control unit configured to control the linear motion member to contact the piston when the vehicle is determined to affect the responsiveness of the vehicle and when the vehicle is in an unlocked state. Brake device.   The said control part becomes a structure which drives the said electric motor and adjusts the clearance clearance between the said piston and a linear motion member, when controlling the said linear motion member to contact the said piston. Brake equipment.

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