JP2017065374A - Brake device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake device capable of suppressing excessive restriction on an operation (holding and releasing) of a parking brake.SOLUTION: A parking brake control device 22 includes abnormality detection means for detecting abnormality of a rotation-linear motion conversion mechanism 40, and stopping the drive of an electric motor 43B, operation continuation propriety detection means for detecting whether or not operation continuation of the rotation-linear motion conversion mechanism 40 is possible when abnormality is detected by the abnormality detection means, and operation resumption permission means for resuming the drive of the electric motor 43B when it is detected by the operation continuation propriety detection means that the operation continuation of the rotation-linear motion conversion mechanism 40 is possible. Therefore, the parking brake control device 22 can resume the drive of the electric motor 43B when the operation continuation of the rotation-linear motion conversion mechanism 40 is possible even if abnormality of the rotation-linear motion conversion mechanism 40 is detected.SELECTED DRAWING: Figure 2

Description

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

  As a brake device provided in a vehicle such as an automobile, a brake device with an electric parking brake function that operates based on driving of an electric motor is known. Such a brake device is configured to apply a parking brake by, for example, propelling a pressing member of a brake mechanism with an electric motor and holding the propelled pressing member with a pressing member holding mechanism (Patent Document 1). ).

  Here, in Patent Document 1, when the pressing member holding mechanism of one of the left and right brake mechanisms fails, the other pressing member holding mechanism is in the released state (release state). A configuration is described in which the release operation (release operation) of the brake mechanism is permitted and the release operation of the other brake mechanism is prohibited in the holding state (apply state).

JP 2014-108655 A

  By the way, when an abnormality of the pressing member holding mechanism is detected, whatever abnormality is detected, it is determined that all the abnormality is a failure, and the driving of the electric motor is completely prohibited from that point. Can be considered. However, in this case, holding (applying) or releasing (release) the parking brake may be excessively limited.

  The objective of this invention is providing the brake device which can suppress that the action | operation (a holding | maintenance, cancellation | release) of a parking brake is restrict | limited excessively.

  In order to solve the above-described problems, a brake device according to the present invention uses a pressing member to propel a friction member disposed so as to be able to contact each rotating member that rotates together with at least a pair of wheels of a vehicle based on an operation of a brake pedal. The brake mechanism, the pressing member of each brake mechanism is propelled by an electric motor, the pressing member holding mechanism that holds the pushed pressing member, and whether the electric motor can be controlled with respect to the operation request signal are switched to the operation request signal. Control means for storing the holding state or release state of the pressing member by the pressing member holding mechanism upon completion of the corresponding operation, and the control means within a predetermined time during operation according to the operation request signal Abnormality detecting means for detecting an abnormality of the pressing member holding mechanism according to the situation and stopping the operation of the pressing member holding mechanism, and the abnormality detection When the abnormality is detected by the means, whether or not the operation of the pressing member holding mechanism can be continued is detected from the control content to the electric motor when the abnormality detection means detects the abnormality. And an operation resuming permission means for allowing the operation of the pressing member holding mechanism to be resumed when it is detected that the operation of the pressing member holding mechanism can be continued. It has composition which has.

  The brake device of the present invention can suppress that the operation (holding and releasing) of the parking brake is restricted excessively.

The conceptual diagram of the vehicle carrying the brake device by embodiment. The longitudinal cross-sectional view which expands and shows the disc brake with an electric parking brake function provided in the rear-wheel side in FIG. The block diagram which shows the parking brake control apparatus in FIG. The flowchart which shows the control processing by a parking brake control apparatus. The flowchart which shows the Apply control process in FIG. 4 by 1st Embodiment. The flowchart which shows the release control process in FIG. 4 by 1st Embodiment. The flowchart which shows the apply control process in FIG. 4 by 2nd Embodiment. The flowchart which shows the release control process in FIG. 4 by 2nd Embodiment.

  Hereinafter, the brake device according to the embodiment will be described with reference to the accompanying drawings, taking as an example a case where the brake device is mounted on a four-wheeled vehicle. Each step of the flowcharts shown in FIGS. 4 to 8 uses the notation “S”, and for example, step 1 is indicated as “S1”.

  1 to 6 show a first embodiment. In FIG. 1, on the lower side (road surface side) of the vehicle body 1 constituting the vehicle body, for example, a total of four front wheels 2 (FL, FR) and left and right rear wheels 3 (RL, RR). Wheels are provided. The wheels (each front wheel 2 and each rear wheel 3) constitute a vehicle together with the vehicle body 1.

  The front wheel 2 and the rear wheel 3 are provided with disc rotors 4 as rotating members (braking members) that rotate together with the respective wheels (the front wheels 2 and the rear wheels 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 31 with an electric parking brake function. The Thereby, a braking force is applied to each wheel (each front wheel 2, each rear wheel 3) independently of each other.

  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 during the braking operation of the vehicle. Based on this operation, the disc brakes 5 and 31 are applied and released as a service brake (service brake). The brake pedal 6 is provided with a brake operation detection sensor (brake sensor) 6A such as a brake lamp switch, a pedal switch, and a pedal stroke sensor. The brake operation detection sensor 6 </ b> A detects whether or not the brake pedal 6 is depressed, or the operation amount thereof, and outputs a detection signal to the hydraulic pressure supply controller 13. The detection signal of the brake operation detection sensor 6A is transmitted, for example, via a vehicle data bus 16 or a signal line (not shown) connecting the hydraulic pressure supply device controller 13 and the parking brake control device 22 ( Output to the parking brake control device 22).

  The depression operation of the brake pedal 6 is transmitted to the master cylinder 8 that functions as a hydraulic pressure source via 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 generates hydraulic pressure with 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 disposed between each of the disc brakes 5, 31 and the master cylinder 8, and distributes the hydraulic pressure from the master cylinder 8 to each of the disc brakes 5, 31 via the brake side piping portions 12A, 12B, 12C, 12D. To do. Thereby, a braking force is applied to each of the wheels (each front wheel 2 and each rear wheel 3) independently of each other. In this case, even if the ESC 11 does not follow the operation amount of the brake pedal 6, the ESC 11 can supply the hydraulic pressure to the disc brakes 5, 31, that is, increase the hydraulic pressure of the disc brakes 5, 31.

  For this purpose, the ESC 11 has a dedicated control device configured by, for example, a microcomputer, that is, a hydraulic pressure supply device controller 13 (hereinafter referred to as a control unit 13). The control unit 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 controlling the brake side. Control is performed to increase, decrease or maintain the brake fluid pressure supplied from the piping parts 12A to 12D to the respective disc brakes 5, 31. As a result, various brake controls such as boost control, braking force distribution control, brake assist control, antilock brake control (ABS), traction control, vehicle stabilization control (including skid prevention), slope start assist control, Automatic operation control or the like is executed.

  The control unit 13 is supplied with power from the battery 14 through the power supply line 15. As shown in FIG. 1, the control unit 13 is connected to a vehicle data bus 16. A known ABS unit can be used instead of the ESC 11. Furthermore, it is also possible to directly connect the master cylinder 8 and the brake side piping parts 12A to 12D without providing the ESC 11 (that is, omitted).

  The vehicle data bus 16 constitutes a CAN (Controller Area Network) as a serial communication unit mounted on the vehicle body 1. The vehicle data bus 16 performs multiplex communication within the vehicle with a large number of electronic devices mounted on the vehicle, the control unit 13, the parking brake control device 22, and the like. In this case, vehicle information sent to the vehicle data bus 16 includes, for example, a brake operation detection sensor 6A, a pressure sensor 17 for detecting a master cylinder hydraulic pressure (brake hydraulic pressure), an ignition switch, a seat belt sensor, a door lock sensor, Door open sensor, seating sensor, vehicle speed sensor, steering angle sensor, accelerator sensor (accelerator operation sensor), throttle sensor, engine rotation sensor, stereo camera, millimeter wave radar, gradient sensor, shift sensor, acceleration sensor, wheel speed sensor, vehicle The information (vehicle information) by the detection signal from the pitch sensor etc. which detect the motion of the pitch direction of this is mentioned.

  A parking brake switch (PKBSW) 21 is provided in the vehicle body 1 at a position near the driver's seat (not shown). The parking brake switch 21 is an operation instruction unit operated by the driver. The parking brake switch 21 generates a signal (operation request signal) corresponding to a parking brake operation request (an apply request that is a holding request, a release request that is a release request) in accordance with a driver's operation instruction. To communicate. That is, the parking brake switch 21 is an operation for applying (holding) or releasing (release) the piston 39 and the brake pad 33 (see FIG. 2) based on the drive (rotation) of the electric motor 43B. A request signal (an apply request signal serving as a holding request signal and a release request signal serving as a release request signal) is output to the parking brake control device 22 serving as a control unit (controller).

  When the driver operates the parking brake switch 21 to the braking side (apply side), that is, when there is an apply request (holding request, driving request) for applying braking force to the vehicle, the parking brake switch 21 An apply request signal is output from. In this case, electric power for rotating the electric motor 43B to the braking side is supplied to the disc brake 31 for the rear wheel 3 via the parking brake control device 22. As a result, the disc brake 31 for the rear wheel 3 is in a state where a braking force as a parking brake (or auxiliary brake) is applied, that is, in an applied state (holding state).

  On the other hand, when the driver operates the parking brake switch 21 to the braking release side (release side), that is, when there is a release request (release request) for releasing the braking force of the vehicle, the parking brake switch 21 Outputs a release request signal. In this case, electric power for rotating the electric motor 43B in the direction opposite to the braking side is supplied to the disc brake 31 via the parking brake control device 22. As a result, the disc brake 31 for the rear wheel 3 is in a state where the application of the braking force as the parking brake (or auxiliary brake) is released, that is, in the released state (released state).

  For example, the parking brake is stopped when the vehicle stops for a predetermined time (for example, it is determined to stop when the vehicle speed sensor detects that the speed detected by the vehicle speed sensor is less than 6 km / h continues for a predetermined time during deceleration). When the shift lever is operated to P, when the door is opened, when the seat belt is released, etc., based on the automatic apply request by the parking brake apply determination logic in the parking brake control device 22, It can be configured to automatically give (auto apply). In addition, the parking brake is used when, for example, the vehicle travels (for example, it is determined that the vehicle travels when the detection speed of the vehicle speed sensor is 5 km / h or more continues for a predetermined time as the vehicle speed increases from when the vehicle is stopped). Is operated, when the clutch pedal is operated, when the shift lever is operated other than P, N, etc., based on the automatic release request by the parking brake release determination logic in the parking brake control device 22 It can be configured to automatically release (auto release). Auto-apply and auto-release may be configured as an auxiliary function at the time of a switch failure that automatically applies or releases a braking force when the parking brake switch 21 fails.

  Furthermore, when there is an apply request by the parking brake switch 21 during traveling of the vehicle, more specifically, a request for dynamic parking brake (dynamic apply) such as urgently using the parking brake as an auxiliary brake during traveling. If there is, for example, the braking force is applied while the parking brake switch 21 is operated to the braking side (while the operation to the braking side is continued), and the application of the braking force is released when the operation ends. Is done. At this time, the parking brake control device 22 applies and releases braking force in order to release this depending on the state of the wheels (each rear wheel 3), that is, whether or not the wheels are locked (slip). Can also be configured (ABS control).

  Next, the structure of the disc brakes 31 and 31 with the electric parking brake function provided on the left and right rear wheels 3 and 3 will be described with reference to FIG. In FIG. 2, only one of the left and right disc brakes 31, 31 provided corresponding to the left and right rear wheels 3, 3 is shown as a representative example.

  A pair of disc brakes 31 provided on the left and right sides of the vehicle are configured as hydraulic disc brakes provided with an electric parking brake function. The disc brake 31 constitutes a brake system together with the parking brake control device 22. The disc brake 31 includes a mounting member 32 attached to a non-rotating portion on the rear wheel 3 side of the vehicle, an inner side and outer side brake pad 33 as a friction member (braking member), and a brake provided with an electric actuator 43. It includes a caliper 34 as a mechanism.

  In this case, the disc brake 31 extends the wheel (rear wheel 3) by propelling the brake pad 33 with the piston 39 by the hydraulic pressure based on the operation of the brake pedal 6 and the like, and pressing the disc rotor 4 with the brake pad 33. Applies braking force to the vehicle. In addition to this, the disc brake 31 is rotated by the electric motor 43B according to the operation request based on the signal from the parking brake switch 21, the above-described parking brake apply / release determination logic, and the operation request based on the ABS control (rotation). The piston 39 is propelled (via the linear motion conversion mechanism 40) to apply a braking force to the vehicle. In this case, the disc brake 31 is provided on each of the left and right wheels of the vehicle, in the embodiment, on each of the left and right rear wheels 3 and 3.

  The mounting member 32 includes a pair of arm portions (not shown) that extend in the axial direction of the disk rotor 4 (that is, the disk axial direction) so as to straddle the outer periphery of the disk rotor 4, and are separated from each other in the disk circumferential direction. A thick-walled support portion 32A that is fixed to a non-rotating portion of the vehicle at a position on the inner side of the disk rotor 4 and is connected to the base end side of the disk rotor 4; And a reinforcing beam 32B for connecting the distal end sides of the arm portions to each other.

  The brake pads 33 on the inner side and the outer side are disposed so as to be able to contact both surfaces of the disk rotor 4 and are supported by the respective arm portions of the mounting member 32 so as to be movable in the disk axial direction. The brake pads 33 on the inner side and the outer side are pressed against both sides of the disc rotor 4 by calipers 34 (the claw portions 38 and the pistons 39 of the caliper main body 35). Thereby, the brake pad 33 gives a braking force to the vehicle by pressing the disc rotor 4 that rotates together with the wheels (rear wheels 3).

  A caliper 34 serving as a wheel cylinder is disposed on the mounting member 32 so as to straddle the outer peripheral side of the disk rotor 4. The caliper 34 is provided so as to be slidably inserted into the caliper main body 35 and supported by the caliper main body 35 movably supported along the axial direction of the disc rotor 4 with respect to the respective arm portions of the mounting member 32. And a piston 39. The caliper 34 is provided with a rotation / linear motion conversion mechanism 40 and an electric actuator 43 which will be described later. The caliper 34 is a brake mechanism that propels the brake pad 33 with the piston 39 based on the operation of the brake pedal 6.

  The caliper body 35 includes an inner cylinder portion 36, a bridge portion 37, and an outer claw portion 38. The cylinder portion 36 is formed in a bottomed cylindrical shape in which one side in the axial direction is closed by a partition wall portion 36 </ b> A and the other side facing the disk rotor 4 is opened. The bridge portion 37 is formed to extend from the cylinder portion 36 in the disc axial direction so as to straddle the outer peripheral side of the disc rotor 4. The claw portion 38 is disposed so as to extend radially inward from the bridge portion 37 on the side opposite to the cylinder portion 36.

  The cylinder portion 36 of the caliper main body 35 is supplied with hydraulic pressure accompanying the depression operation of the brake pedal 6 or the like via the brake side piping portion 12C or 12D shown in FIG. The cylinder portion 36 is integrally formed with the partition wall portion 36A. The partition wall portion 36 </ b> A is located between the cylinder portion 36 and the electric actuator 43. The partition wall portion 36A has a through hole in the axial direction, and an output shaft 43C of the electric actuator 43 is rotatably inserted on the inner peripheral side of the partition wall portion 36A.

  In the cylinder part 36 of the caliper main body 35, a piston 39 as a pressing member (moving member) and a rotation / linear motion conversion mechanism 40 are provided. In the embodiment, the rotation / linear motion conversion mechanism 40 is accommodated in the piston 39. However, the rotation / linear motion conversion mechanism 40 only needs to be configured to propel the piston 39 and does not necessarily have to be accommodated in the piston 39. That is, the rotation / linear motion conversion mechanism 40 serving as the pressing member holding mechanism may be provided at a non-rotating portion of the vehicle.

  The piston 39 moves the brake pad 33 in a direction in which the brake pad 33 is separated from or in contact with the disk rotor 4 (a direction toward the disk rotor 4 or a direction away from the disk rotor 4). The piston 39 is open on one side in the axial direction, and the other side in the axial direction facing the inner brake pad 33 is closed by a lid portion 39A. The piston 39 is inserted into the cylinder part 36.

  In addition to the movement of the piston 39 when electric current is supplied to the electric actuator 43 (electric motor 43B), the hydraulic pressure is supplied into the cylinder portion 36 based on the depression of the brake pedal 6 or the like. Moving. In this case, the movement of the piston 39 by the electric actuator 43 (electric motor 43B) is performed by being pressed by the linear motion member. Further, the rotation / linear motion conversion mechanism 40 is accommodated in a piston 39, and the piston 39 is configured to be propelled in the axial direction of the cylinder portion 36 by the rotation / linear motion conversion mechanism 40.

  The rotation / linear motion conversion mechanism 40 functions as a pressing member holding mechanism. Specifically, the rotation / linear motion conversion mechanism 40 propels the piston 39 by propelling the piston 39 by an external force different from the force generated by applying the hydraulic pressure into the cylinder portion 36, that is, the force generated by the electric actuator 43. (And thus the brake pad 33) is held. Thereby, a parking brake will be in an applied state (holding state). On the other hand, the rotation / linear motion conversion mechanism 40 retracts the piston 39 in the direction opposite to the propulsion direction by the electric actuator 43, and sets the parking brake to the released state (released state). Since the left and right disc brakes 31 are respectively provided for the left and right rear wheels 3, the rotation / linear motion conversion mechanism 40 and the electric actuator 43 are also provided on each of the left and right sides of the vehicle.

  The rotation / linear motion conversion mechanism 40 includes a screw member 41 having a rod-like body in which a male screw such as a trapezoidal screw is formed, and a linear motion member 42 in which a female screw hole formed by the trapezoidal screw is formed on the inner peripheral side (spindle). Configured as a nut mechanism). The linear motion member 42 is a driven member (propulsion member) that moves toward the piston 39 by the electric actuator 43 or in a direction away from the piston 39. That is, the screw member 41 screwed to the inner peripheral side of the linear motion member 42 constitutes a screw mechanism that converts the rotational motion by the electric actuator 43 into the linear motion of the linear motion member 42. In this case, the female screw of the linear motion member 42 and the male screw of the screw member 41 form a pressing member holding mechanism by using a highly irreversible screw, in the embodiment, a trapezoidal screw.

  The pressing member holding mechanism (rotation / linear motion converting mechanism 40) holds the linear motion member 42 (that is, the piston 39) at an arbitrary position by a frictional force (holding force) even when power supply to the electric motor 43B is stopped. It has become. The pressing member holding mechanism only needs to be able to hold the piston 39 at a position propelled by the electric actuator 43. For example, the pressing member holding mechanism may be a normal triangular cross-section screw or a worm gear with large irreversibility other than a trapezoidal screw.

  The screw member 41 that is screwed to the inner peripheral side of the linear motion member 42 is provided with a flange portion 41A that is a large-diameter flange on one side in the axial direction. The other side of the screw member 41 in the axial direction extends toward the lid portion 39 </ b> A of the piston 39. The screw member 41 is integrally connected to the output shaft 43C of the electric actuator 43 at the flange portion 41A. Further, on the outer peripheral side of the linear motion member 42, the linear motion member 42 is prevented from rotating with respect to the piston 39 (relative rotation is restricted), and the linear motion member 42 is allowed to relatively move in the axial direction. A protrusion 42A is provided. Thereby, the linear motion member 42 moves linearly when the electric motor 43B is driven, contacts the piston 39, and moves the piston 39.

  The electric actuator 43 is fixed to the caliper body 35 of the caliper 34. The electric actuator 43 operates (applies / releases) the disc brake 31 based on the operation request signal of the parking brake switch 21, the above-described parking brake apply / release determination logic, and ABS control. The electric actuator 43 includes a casing 43A attached to the outside of the partition wall portion 36A, an electric motor 43B that is located in the casing 43A, includes a stator and a rotor, and moves the piston 39 when supplied with electric power (current). A reduction gear (not shown) that increases the torque of the electric motor 43B and an output shaft 43C that outputs rotational torque after the reduction by the reduction gear are configured. The electric motor 43B is configured as an electric motor such as a DC brush motor, for example. The output shaft 43C extends through the partition wall portion 36A of the cylinder portion 36 in the axial direction, and at the end of the flange portion 41A of the screw member 41 in the cylinder portion 36 so as to rotate integrally with the screw member 41. It is connected.

  For example, the coupling mechanism between the output shaft 43C and the screw member 41 can be configured to be movable in the axial direction but to be prevented from rotating 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. As the speed reducer, for example, a planetary gear speed reducer or a worm gear speed reducer may be used. Further, when a known speed reducer having no reverse operation (irreversible) such as a worm gear speed reducer is used, the reversible known mechanism such as a ball screw or a ball ramp mechanism is used as the rotation / linear motion converting mechanism 40. Can be used. In this case, for example, the pressing member holding mechanism can be configured by a reversible rotation / linear motion conversion mechanism and an irreversible speed reducer.

  When the driver operates the parking brake switch 21 shown in FIGS. 1 to 3, power is supplied to the electric motor 43 </ b> B via the parking brake control device 22, and the output shaft 43 </ b> C of the electric actuator 43 is rotated. For this reason, the screw member 41 of the rotation / linear motion conversion mechanism 40 is rotated integrally with the output shaft 43C in one direction, and propels (drives) the piston 39 toward the disk rotor 4 via the linear motion member 42. As a result, the disc brake 31 is in a state where the disc rotor 4 is sandwiched between the inner side and outer side brake pads 33 and a braking force is applied as an electric parking brake, that is, in an applied state (holding state).

  On the other hand, when the parking brake switch 21 is operated to the brake release side, the screw member 41 of the rotation / linear motion conversion mechanism 40 is rotationally driven in the other direction (reverse direction) by the electric actuator 43. As a result, the linear motion member 42 (and the piston 39 if no hydraulic pressure is applied) is driven in a direction away from the disc rotor 4, and the disc brake 31 is in a state in which the application of the braking force as a parking brake is released, that is, , The release state (release state).

  In this case, in the rotation / linear motion converting mechanism 40, when the screw member 41 is rotated relative to the linear motion member 42, the rotation of the linear motion member 42 within the piston 39 is restricted. Moves relatively in the axial direction according to the rotation angle of the screw member 41. Thereby, the rotation / linear motion converting mechanism 40 converts the rotational motion into a linear motion, and the piston 39 is driven by the linear motion member 42. At the same time, the rotation / linear motion conversion mechanism 40 holds the linear motion member 42 at an arbitrary position by a frictional force with the screw member 41, so that the piston 39 and the brake pad 33 are propelled by the electric actuator 43. Hold on.

  A thrust bearing 44 is provided on the partition wall portion 36 </ b> A of the cylinder portion 36 between the partition wall portion 36 </ b> A and the flange portion 41 </ b> A of the screw member 41. The thrust bearing 44 receives a thrust load from the screw member 41 together with the partition wall portion 36A, and smoothly rotates the screw member 41 with respect to the partition wall portion 36A. In addition, a seal member 45 is provided between the partition wall portion 36A of the cylinder portion 36 and the output shaft 43C of the electric actuator 43. The seal member 45 leaks brake fluid in the cylinder portion 36 to the electric actuator 43 side. It seals between the two so as to prevent it.

  A piston seal 46 as an elastic seal that seals between the cylinder portion 36 and the piston 39 and a dust boot 47 that prevents foreign matter from entering the cylinder portion 36 are provided on the opening end side of the cylinder portion 36. It has been. The dust boot 47 is a flexible bellows-like seal member, and is attached between the opening end of the cylinder portion 36 and the outer periphery of the piston 39 on the lid portion 39A side.

  The disc brake 5 for the front wheel 2 is configured in substantially the same manner as the disc brake 31 for the rear wheel 3 except for the parking brake mechanism. That is, the disc brake 5 for the front wheel 2 does not include the rotation / linear motion conversion mechanism 40 that operates as a parking brake, the electric actuator 43, and the like provided in the disc brake 31 for the rear wheel 3. However, instead of the disc brake 5, a disc brake 31 with an electric parking brake function may be provided for the front wheel 2.

  In the embodiment, the hydraulic disc brake 31 including the electric actuator 43 has been described as an example. However, for example, an electric disc brake with an electric caliper, an electric drum brake that applies a braking force by pressing a shoe against the drum by an electric actuator, a disc brake with an electric drum type parking brake, and a cable with an electric actuator The frictional force (pad, shoe) is pressed (promoted) against the rotating member (rotor, drum) based on the drive of the electric actuator (electric motor), such as applying the parking brake by pulling, and the pressing force If it is the structure which can hold | maintain, it may not be the structure of the above-mentioned embodiment.

  The brake device for a four-wheeled vehicle according to the 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 to the disc brakes 5 and 31 via the cylinder side hydraulic pipes 10A and 10B, the ESC 11 and the brake side pipe sections 12A, 12B, 12C and 12D, and the left and right front wheels 2 A braking force is applied to each of the left and right rear wheels 3.

  The disc brake 31 for the rear wheel 3 will be described. The hydraulic pressure is supplied into the cylinder portion 36 of the caliper 34 via the brake side piping portions 12C and 12D, and the piston 39 is slidably displaced toward the brake pad 33 on the inner side as the hydraulic pressure in the cylinder portion 36 increases. To do. Accordingly, the piston 39 presses the inner brake pad 33 against one side surface of the disk rotor 4. Due to the reaction force at this time, the entire caliper 34 is slidably displaced toward the inner side with respect to the respective arm portions of the mounting member 32.

  As a result, the outer leg portion (claw portion 38) of the caliper 34 operates so as to press the brake pad 33 on the outer side against the disc rotor 4, and the disc rotor 4 is moved in the axial direction by the pair of brake pads 33. It is clamped from both sides. Thereby, a braking force based on the hydraulic pressure is generated. On the other hand, when the brake operation is released, the supply of the hydraulic pressure into the cylinder portion 36 is stopped, so that the piston 39 is displaced so as to retract into the cylinder portion 36. As a result, the inner-side and outer-side brake pads 33 are separated from the disc rotor 4, and the vehicle is returned to the non-braking state.

  Next, when the driver of the vehicle operates the parking brake switch 21 to the braking side (ON), power is supplied from the parking brake control device 22 to the electric motor 43B of the disc brake 31, and the output shaft 43C of the electric actuator 43 is Driven by rotation. The disc brake 31 with the electric parking brake function converts the rotational motion of the electric actuator 43 into the linear motion of the linear motion member 42 via the screw member 41 of the rotational linear motion conversion mechanism 40, and the linear motion member 42 in the axial direction. The piston 39 is propelled by moving it. As a result, the pair of brake pads 33 are pressed against both surfaces of the disc rotor 4.

  At this time, the linear motion member 42 is held in a braking state by a frictional force (holding force) generated between the linear motion member 42 and the screw member 41 using the pressing reaction force transmitted from the piston 39 as a vertical reaction force. The disc brake 31 is operated (applied) as a parking brake. That is, even after the power supply to the electric motor 43B is stopped, the linear motion member 42 (and thus the piston 39) is held in the braking position by the female screw of the linear motion member 42 and the male screw of the screw member 41.

  On the other hand, when the driver operates the parking brake switch 21 to the brake release side (off), electric power is supplied from the parking brake control device 22 so as to reverse the motor to the electric motor 43B, and the output shaft 43C of the electric actuator 43 is When the parking brake is activated (apply), it is rotated in the opposite direction. At this time, the holding of the braking force by the screw member 41 and the linear motion member 42 is released, and the rotation / linear motion conversion mechanism 40 moves the linear motion member 42 in the return direction by a movement amount corresponding to the reverse rotation amount of the electric actuator 43. That is, it is moved into the cylinder portion 36, and the braking force of the parking brake (disc brake 31) is released.

  Next, the parking brake control device 22 will be described with reference to FIG.

  The parking brake control device 22 as a control means constitutes a brake system together with a pair of left and right disc brakes 31, 31. The parking brake control device 22 has an arithmetic circuit (CPU) 23 configured by a microcomputer or the like, and the parking brake control device 22 is supplied with power from the battery 14 through the power supply line 15.

  The parking brake control device 22 controls the electric motors 43B and 43B of the disc brakes 31 and 31 on the left rear wheel 3 side and the right rear wheel 3 side to control when the vehicle is parked or stopped (when necessary, traveling). Generate power (parking brake, auxiliary brake). That is, the parking brake control device 22 operates (applies and releases) the disc brakes 31 and 31 as parking brakes (auxiliary brakes as necessary) by driving the left and right electric motors 43B and 43B. For this purpose, as shown in FIGS. 1 to 3, the parking brake control device 22 has an input side connected to the parking brake switch 21 and an output side connected to the electric motors 43B and 43B of the disc brakes 31 and 31, respectively. Yes.

  The parking brake control device 22 is controlled based on the operation request (apply request, release request) by the driver's operation of the parking brake switch 21, the operation request by the apply / release judgment logic of the parking brake, and the operation request by ABS control. The electric motors 43B and 43B are driven to apply (hold) or release (release) the left and right disc brakes 31 and 31. At this time, in each of the disc brakes 31, 31, the piston 39 and the brake pad 33 are held or released by the pressing member holding mechanism (rotation linear motion conversion mechanism 40) based on the driving of each electric motor 43 </ b> B. That is, the parking brake control device 22 responds to an operation request signal for holding operation (apply) or release operation (release) of the piston 39 (and thus the brake pad 33), and thereby the piston 39 (and thus the brake pad 33). ) To drive the electric motor 43B.

  As shown in FIG. 3, the arithmetic circuit (CPU) 23 of the parking brake control device 22 includes a parking brake switch 21, a vehicle data bus 16, a voltage sensor unit 25, a motor drive circuit, in addition to a memory 24 as a storage unit. 26, a current sensor unit 27, and the like are connected. From the vehicle data bus 16, various state quantities of the vehicle necessary for the control (operation) of the parking brake, that is, various vehicle information can be acquired.

  Note that the vehicle information acquired from the vehicle data bus 16 may be acquired by directly connecting a sensor that detects the information to the parking brake control device 22 (the arithmetic circuit 23 thereof). The arithmetic circuit 23 of the parking brake control device 22 is configured such that an operation request based on the above-described determination logic or ABS control is input from another control device (for example, the control unit 13) connected to the vehicle data bus 16. May be. In this case, the determination of parking brake apply / release and the ABS control by the above-described determination logic may be performed by another control device, for example, the control unit 13, instead of the parking brake control device 22. That is, it is possible to integrate the control content of the parking brake control device 22 into the control unit 13.

  The parking brake control device 22 includes a memory 24 including, for example, a flash memory, a ROM, a RAM, an EEPROM, and the like. The memory 24 stores a parking brake apply / release determination logic and an ABS control program. In addition to this, the memory 24 includes a processing program for executing the processing flows shown in FIGS. 4 to 6, that is, determination of whether or not the electric motor 43 </ b> B can be controlled with respect to an operation request signal (apply request signal, release request signal). In accordance with the determination, a processing program is stored for switching whether control is possible or not (engagement of braking) or release (release of braking) of the disc brake 31.

  Further, the memory 24 of the parking brake control device 22 stores the holding state or the releasing state of the piston 39 by the rotation / linear motion conversion mechanism 40 when the operation according to the operation request signal is completed. Specifically, the state (for example, the holding state, the released state, and the unknown state) of the piston 39 by the rotation / linear motion converting mechanism 40 is stored in the memory 24 every time the state (status) is changed. That is, the arithmetic circuit 23 of the parking brake control device 22 determines whether the state of the disc brake 31 (piston 39) is in the holding state, the released state, or the unknown state, and the determination result is as needed or It is stored in the memory 24 at the timing of the activation process.

  Specifically, in the arithmetic circuit 23, when the holding of the piston 39 by the rotation / linear motion converting mechanism 40 is completed, the holding flag is turned ON, and when the release of the piston 39 is completed, the releasing flag is turned ON. The state of the piston 39 by the rotation / linear motion converting mechanism 40 is stored in the memory 24 as a “holding state (fastened state)” when the holding flag is ON, and as a “released state” when the release flag is ON. Is done.

  Further, for example, when the drive of the electric motor 43B is completed after the drive of the electric motor 43B is started and before the holding flag or the release flag is turned ON, for example, the power supply to the parking brake control device 22 is interrupted. If it is neither “holding state” nor “released state”, such as when it is struck, it is stored in the memory 24 as an “unknown state”. That is, when the operation is started from the “release state” to the “hold state” or when the operation is started from the “hold state” to the “release state”, the “unknown state” is stored in the memory 24. It has become so.

  The state of the rotation / linear motion conversion mechanism 40 (state of the piston 39) stored in the memory 24 is when the power of the power supply line 15 becomes unstable and temporarily decreases, that is, to the parking brake control device 22. Non-volatile storage device (memory) that can maintain memory without power supply so that it can be used immediately even when the power supply is cut off (system goes down) and then the power is restored and the system is restarted For example, it is stored in an EEPROM.

  In the embodiment, the parking brake control device 22 is separated from the control unit 13 of the ESC 11, but the parking brake control device 22 may be integrated with the control unit 13. Further, the parking brake control device 22 controls the two disc brakes 31 and 31 on the left and right, but may be provided for each of the left and right disc brakes 31 and 31. The parking brake control device 22 can also be provided integrally with the disc brake 31.

  As shown in FIG. 3, the parking brake control device 22 includes a voltage sensor unit 25 that detects a voltage from the power supply line 15, left and right motor drive circuits 26 and 26 that respectively drive the left and right electric motors 43 </ b> B and 43 </ b> B, The left and right current sensor units 27, 27, etc. for detecting the respective motor currents of the electric motors 43B, 43B are incorporated. The voltage sensor unit 25, the motor drive circuit 26, and the current sensor unit 27 are connected to the arithmetic circuit 23, respectively.

  Thereby, in the arithmetic circuit 23 of the parking brake control device 22, when applying or releasing, the disk rotor 4 and the disk rotor 4 are changed based on the change in the motor current of the electric motors 43B and 43B detected by the current sensor units 27 and 27. Determination of contact / separation with the brake pad 33, determination of thrust by driving the electric motors 43B, 43B, determination of stop of driving of the electric motors 43B, 43B (determination of apply completion, determination of release completion), etc. be able to. In this case, for example, when the motor current value reaches a preset holding threshold value or release threshold value, the arithmetic circuit 23 determines that the state of the piston 39 by the rotation / linear motion conversion mechanism 40 is in the holding state or the release state. Then, the drive of the electric motor 43B is stopped. This process is performed independently for each of the left and right disc brakes 31 (each of the left and right electric motors 43B), for example.

  Furthermore, the parking brake control device 22 performs abnormality diagnosis of the electric actuators 43 and 43 including the motor drive circuits 26 and 26 and the electric motors 43B and 43B based on the current and voltage. For example, the arithmetic circuit 23 of the parking brake control device 22 determines the left and right electric motors 43B and 43B according to the voltage VB (voltage input to the parking brake control device 22) from the power line 15 and the left and right electric motors 43B and 43B. An abnormality of the disc brakes 31, 31, more specifically, an abnormality of the left / right rotation / linear motion conversion mechanism 40 and the electric actuator 43 is detected (diagnosed).

  In this case, as will be described later, the parking brake control device 22 rotates based on, for example, a change in the motor current value during the apply operation or the release operation, a time required to complete the apply operation or the release operation, and the like. It is determined what abnormality is in the linear motion conversion mechanism 40. In addition, the parking brake control device 22 performs abnormality determination independently for each of the left and right disc brakes 31 (for each of the left and right electric motors 43B). Thereby, it is possible to determine whether both wheels are normal, left wheel is abnormal, right wheel is abnormal, or both wheels are abnormal.

  Here, when an abnormality of the rotation / linear motion converting mechanism 40 is detected, it is determined that all the abnormality is a failure, and the driving of the electric motor 43B is completely prohibited from that point. It is conceivable to have a configuration. However, in this case, holding (applying) or releasing (release) the parking brake may be excessively limited.

  Therefore, in the embodiment, the parking brake control device 22 includes an abnormality detecting means (S12, S13, S18 in FIG. 5, S32, S33, S38 in FIG. 6) and an operation continuation possibility detecting means (S19 in FIG. 5, FIG. 6). S39) and an operation resuming permission means (S3 in FIG. 4, S20 in FIG. 5, S40 in FIG. 6).

  The anomaly detection means is configured to rotate in accordance with a situation within a predetermined time (for example, a situation of a change in the motor current value within the predetermined time) during operation according to the operation request signal (apply request signal, release request signal). An abnormality of the dynamic conversion mechanism 40 is detected (S12 in FIG. 5 and S32 in FIG. 6). Then, when detecting the abnormality, the abnormality detecting means stops the driving of the electric motor 43B in order to stop the operation of the rotation / linear motion converting mechanism 40 (S13, S18 in FIG. 5, S33, S38 in FIG. 6).

  Here, the abnormality of the rotation / linear motion conversion mechanism 40 can be detected as follows, for example.

  (A). During the apply operation, when the motor current value becomes equal to or greater than the threshold value a1 [A] during the predetermined time t1 [ms] from the start of driving of the electric motor 43B, and the state continues for the predetermined time t2 [ms], for example, It is considered that an abnormality (stack abnormality) in which the rotation / linear motion conversion mechanism 40 does not move has occurred.

  (B). During the release operation, when the motor current value becomes equal to or greater than the threshold value a2 [A] and continues for a predetermined time t3 [ms] in this state, for example, an abnormality that prevents the rotation / linear motion conversion mechanism 40 from moving (stack abnormality) has occurred. Conceivable.

  (C). During the apply operation, the motor current value is equal to or greater than the threshold value a3 [A] in the idle running section before the linear motion member 42 contacts the piston 39 (the lid portion 39A), and this state continues for a predetermined time t4 [ms]. In this case, for example, it is considered that an abnormality in efficiency reduction has occurred in the rotation / linear motion conversion mechanism 40.

  (D). During the apply operation, the time during which the motor current value passes from the lower threshold value a4 [A] to the upper threshold value a5 [A] in a section where the pressing force by the linear motion member 42 increases is determined according to the voltage at that time. If it is shorter than t5 [ms], for example, it is considered that an abnormality in efficiency reduction has occurred in the rotation / linear motion conversion mechanism 40.

  (E). During the release operation, the release is not completed even after a predetermined time t6 [ms] has elapsed from the start of the driving of the electric motor 43B (corresponding to the last retreat position where the motor current value did not reach the release completion value). If no change has occurred, for example, it is considered that an abnormality in efficiency reduction has occurred in the rotation / linear motion conversion mechanism 40.

  (F). When the apply state continues for a predetermined time t7 [s] during the apply operation, it is considered that, for example, an abnormality in idling of the rotation / linear motion conversion mechanism 40 has occurred.

  (G). In the release operation, if there is no peak in the change in the motor current value and the applied state continues for a predetermined time t8 [s], it is considered that, for example, an abnormality in idling of the rotation / linear motion conversion mechanism 40 has occurred.

  The predetermined times t1 to t8 and the motor current values a1 to a5 are obtained in advance by experiments, simulations, calculations, etc. so that various abnormalities of the rotation / linear motion conversion mechanism 40 can be accurately detected (set in advance). deep).

  The abnormality detection means stops the driving of the electric motor 43B when detecting any of the abnormalities (a) to (g). In this case, the abnormality detection means turns on a caution lamp (notification device) on an instrument panel provided in front of the driver's seat in order to notify the driver that an abnormality has occurred in the electric parking brake. A configuration may be adopted in which a notification command is output to the notification device. On the other hand, when the abnormality is detected by the abnormality detection means, the operation continuation permission / inhibition detection means is a control content to the electric motor 43B when detecting the abnormality, that is, a motor current value supplied to the electric motor 43B and the motor current value. It is detected (determined) whether or not the operation of the rotation / linear motion converting mechanism 40 can be continued from a predetermined time (supply time) for outputting.

  That is, if the abnormality detected by the abnormality detection means is, for example, (c), (d), or (g), the operation continuation enable / disable detection means can continue the operation of the rotation / linear motion conversion mechanism 40. Is determined. On the other hand, for example, in the case of (a), (b), (e), and (f), the operation continuation permission / inhibition detection unit determines that the operation of the rotation / linear motion conversion mechanism 40 cannot be continued. That is, the operation continuation permission / inhibition detection unit distinguishes whether the detected abnormality is an abnormality that can be applied or released or an abnormality that cannot be applied. In the case of (g), it may be determined that the operation of the rotation / linear motion conversion mechanism 40 cannot be continued.

  Further, the operation resumption permitting means restarts the operation of the rotation / linear motion conversion mechanism 40 when the operation continuation permission / inhibition detection means detects (determines) that the operation of the rotation / linear motion conversion mechanism 40 can be continued. Make it possible. That is, when the operation resumption permitting means can continue the operation, if the operation request signal by the operation instruction after detecting the abnormality by the abnormality detecting means is an apply request signal, the operation resuming permission means restarts the apply operation. If the operation request signal by the operation instruction after detecting the abnormality is a release request signal, the release operation is resumed. In this case, for example, the apply operation or the release operation can be performed even if a warning lamp (notification information) indicating that an abnormality has occurred in the electric parking brake is lit (output) on the instrument panel (notification device). Based on the lighting of the caution lamp, the driver can request a repair shop for repair.

  Next, control processing performed by the arithmetic circuit 23 of the parking brake control device 22 will be described with reference to FIGS. 4 to 6. The process in FIG. 5 corresponds to the apply control process in S5 in FIG. 4, and the process in FIG. 6 corresponds to the release control process in S7 in FIG. The control process of FIG. 4 is repeatedly executed at a predetermined control period, that is, every predetermined time (for example, 10 ms) while the parking brake control device 22 is energized, for example.

  When the parking brake control device 22 is activated and the control process of FIG. 4 is started, it is determined in S1 whether or not there is an operation request signal due to the operation of the parking brake switch 21. If “NO” in S1, that is, if it is determined that there is no operation request signal, the process proceeds to return without performing the processes after S2. On the other hand, if “YES” in S1, that is, if it is determined that there is an operation request signal, the process proceeds to S2. In S2, it is determined whether or not the failure flag is OFF. The failure flag is turned ON by the process of S17 of FIG. 5 or S37 of FIG. If “NO” in S2, that is, if it is determined that the failure flag is not OFF (ON), the process proceeds to S3.

  In S3, it is determined whether the operation continuation possible flag is ON. The operation continuation possible flag is turned on by the process of S20 of FIG. 5 or S40 of FIG. If “NO” in S3, that is, if it is determined that the operation continuation possible flag is OFF (not ON), the process proceeds to SRETRY without performing the processes after S4. In this case, since the abnormality of the rotation / linear motion converting mechanism 40 is detected and the abnormality cannot be continued, the electric motor is not driven even if an apply request or a release request is made as an operation request ( The stop of the electric motor 43B is maintained). In this case, in order to notify the driver that a failure has occurred in the electric parking brake, for example, a warning lamp (notification device) on an instrument panel provided in front of the driver's seat is turned on (notification). A notification command is output to the device). The warning lamp may be, for example, a lamp different from the caution lamp that notifies that an abnormality has occurred in the electric parking brake, or may be the same lamp.

  On the other hand, if “YES” in S2, that is, if the failure flag is determined to be OFF, or if “YES” in S3, that is, if the operation continuation possible flag is determined to be ON, the process proceeds to S4. In S4, it is determined whether or not the operation request signal is an apply request. That is, in S4, it is determined whether or not the operation request signal is an apply request by operating the parking brake switch 21, or an auto-apply request by the above-described determination logic (auto-apply request by ABS control as necessary). If “YES” in S4, that is, if it is determined that the request is an Apply request, the process proceeds to S5.

  In S5, an Apply control process (a control process in FIG. 5 described later) is performed, and when the Apply control process ends (proceeds to return in the process in FIG. 5), the process returns (starts via a return in FIG. 4). , The process after S1 is repeated).

  On the other hand, if “NO” in S4, that is, if it is determined that the operation request signal is not an apply request, the operation request signal is a release request, that is, a release request by the operation of the parking brake switch 21, the aforementioned determination logic Since there is an auto release request by (if necessary, an auto release request by ABS control), the process proceeds to S7.

  In S7, release control processing (control processing in FIG. 6 described later) is performed, and when the release control processing ends (proceeds to return in the processing in FIG. 6), the process returns.

  Next, the apply control process of S5 will be described with reference to FIG.

  When it is determined as “YES” in S4 of FIG. 4 and the application control process of FIG. 5 is started by proceeding to S5, the drive of the electric motor 43B is started in S11. That is, electric power for rotating the electric motor 43B to the braking side (apply side) is supplied. In continuing S12, abnormality of the rotation linear motion conversion mechanism 40 which is a holding mechanism is diagnosed. Specifically, the current sensor units 27 and 27 detect the change state of the motor current value within a predetermined time. In continuing S13, abnormality of the rotation / linear motion conversion mechanism 40 is determined. That is, it is determined whether or not an abnormality during the apply operation among the above (a) to (g), that is, any one of the abnormalities (a), (c), (d), and (f) is detected. .

  If “NO” in S13, that is, if it is determined that there is no abnormality, the process proceeds to S14. In S14, it is determined whether or not the motor current value has reached a predetermined holding current, that is, a current threshold value for completing the application (current value for stopping the electric motor 43B). The predetermined holding current (current threshold value) is obtained in advance (set in advance) by experiment, simulation, calculation, or the like so that the completion of the application can be accurately determined. If “NO” in S14, that is, if it is determined that the motor current value is not the predetermined holding current, the process returns to before S12, and the processes after S12 are repeated. On the other hand, if “YES” in S14, that is, if it is determined that the motor current value has reached the predetermined holding current, the process proceeds to S15. In S15, the electric motor 43B is stopped. That is, the power supply to the electric motor 43B is stopped, and in S21, the fact that the state of the piston 39 by the rotation / linear motion converting mechanism 40 is in the holding state (applied state) is stored in the memory 24, and then the process returns (FIG. 5). Go to S1 in FIG. 4 via the return).

  If “YES” in S13, that is, if it is determined that there is an abnormality, the process proceeds to S16. In S16, it is determined whether an operation continuation possible flag, which will be described later, is ON. If “YES” in S16, that is, if it is determined that the operation continuation possible flag is ON, the process proceeds to S14. On the other hand, if “NO” in S16, that is, if it is determined that the operation continuation possible flag is OFF, the process proceeds to S17, the failure flag is turned ON, and then the electric motor 43B is stopped in S18. That is, power supply to the electric motor 43B is stopped. At this time, a warning lamp (notification device) for notifying the driver that an abnormality has occurred in the electric parking brake is turned on (a notification command is output to the notification device). In subsequent S19, it is determined (detected) whether or not the abnormality of the rotation / linear motion conversion mechanism 40, which is the holding mechanism, is an abnormality that allows the operation to continue. Specifically, it is determined whether or not the abnormality of the rotation / linear motion conversion mechanism 40 is (c) or (d) among the above (a), (c), (d), and (f).

  If “YES” in S19, that is, if it is determined that the abnormality of the rotation / linear motion conversion mechanism 40 is (c) or (d), the process proceeds to S20, and the abnormality detected in S12 is an abnormality that can continue operation. In order to store the fact, the operation continuation possible flag is turned ON, and in S22, the fact that the state of the piston 39 by the rotation / linear motion conversion mechanism 40 is in an unknown state is stored in the memory 24, and then the process returns. Through this return, input of an operation request signal is awaited in the process of S1 in FIG. 4, and when there is an operation request signal, the process proceeds to S4 through the processes of S2 and S3, and the apply control is performed in the subsequent processes. Or, release control is resumed. Thus, even if the failure flag is ON, since the operation continuation possible flag is ON, the operation can be resumed by an Apply request or a release request from the state where the electric motor 43B is stopped due to the abnormality detection. Apply control processing and release control processing are performed. In this case, since the operation continuation enable flag is ON, in the apply control process (process of FIG. 5), “YES” is determined in S16, and the operation can be resumed (continued) by proceeding to S14. it can. In addition, as needed, S51 can be provided between S15 and a return, for example, and an operation continuation possible flag can be turned off.

  On the other hand, if “NO” in S19, that is, if it is determined that the abnormality of the rotation / linear motion conversion mechanism 40 is (a) or (f), the operation continuation possible flag is set to ON without proceeding to S20. (No), in S22, the fact that the state of the piston 39 by the rotation / linear motion converting mechanism 40 is in an unknown state is stored in the memory 24, and then the process proceeds to return. The process proceeds to the return of FIG. 4 via this return, and the process of S1 is repeated. In this case, that is, when the process proceeds from S19 to the return (without proceeding to S20) (when the failure flag is ON and the operation continuation enable flag is OFF), it is determined as “NO” in S2 and S3. Even if there is an operation request signal (apply request or release request), the apply control process and the release control process are not performed (the drive of the electric motor 43B is prohibited).

  Next, the release control process of S7 will be described with reference to FIG.

  When it is determined as “NO” in S4 of FIG. 4 and the release control process of FIG. 6 is started by proceeding to S7, the drive of the electric motor 43B is started in S31. That is, electric power for rotating to the brake release side (release side) is supplied to the electric motor 43B. In subsequent S32, an abnormality of the rotation / linear motion conversion mechanism 40 as a holding mechanism is diagnosed. Specifically, the current sensor units 27 and 27 detect the change state of the motor current value within a predetermined time. In continuing S33, abnormality of the rotation / linear motion conversion mechanism 40 is determined. That is, it is determined whether or not an abnormality during the release operation among the above (a) to (g), that is, any of the abnormalities (b), (e), and (g) is detected.

  If “NO” in S33, that is, if it is determined that there is no abnormality, the process proceeds to S34. In S34, it is determined whether or not the motor current value has reached a predetermined release current, that is, a current value for completing release (a current value for stopping the electric motor 43B). The predetermined release current (current threshold) is obtained in advance (set in advance) by experiment, simulation, calculation, or the like so that the completion of release can be accurately determined. If “NO” in S34, that is, if it is determined that the motor current value is not the predetermined release current, the process returns to before S32, and the processes after S32 are repeated. On the other hand, if “YES” in S34, that is, if it is determined that the motor current value has reached the predetermined release current, the process proceeds to S35. In S35, the electric motor 43B is stopped. That is, the power supply to the electric motor 43B is stopped, and in S41, the fact that the state of the piston 39 by the rotation / linear motion converting mechanism 40 is in the released state (release state) is stored in the memory 24, and then the process returns (FIG. 6). Go to S1 in FIG. 4 via the return).

  If “YES” in S33, that is, if it is determined that there is an abnormality, the process proceeds to S36. In S36, it is determined whether the operation continuation possible flag is ON. If “YES” in S36, that is, if it is determined that the operation continuation possible flag is ON, the process proceeds to S34. On the other hand, if “NO” in S36, that is, if it is determined that the operation continuation possible flag is OFF, the process proceeds to S37, the failure flag is turned ON, and then the electric motor 43B is stopped in S38. That is, power supply to the electric motor 43B is stopped. At this time, a warning lamp (notification device) for notifying the driver that an abnormality has occurred in the electric parking brake is turned on (a notification command is output to the notification device). In subsequent S39, it is determined (detected) whether or not the abnormality of the rotation / linear motion conversion mechanism 40, which is the holding mechanism, is an abnormality that allows the operation to continue. Specifically, it is determined whether or not the abnormality of the rotation / linear motion conversion mechanism 40 is (g) among the above (b), (e), and (g).

  If “YES” in S39, that is, if it is determined that the abnormality of the rotation / linear motion conversion mechanism 40 is (g), the process proceeds to S40, and the abnormality detected in S32 is stored as an abnormality that can be continued. Therefore, the operation continuation possible flag is turned ON, and in S42, the fact that the state of the piston 39 by the rotation / linear motion conversion mechanism 40 is unknown is stored in the memory 24, and then the process returns. Through this return, input of an operation request signal is awaited in the process of S1 in FIG. 4, and when there is an operation request signal, the process proceeds to S4 through the processes of S2 and S3, and the apply control is performed in the subsequent processes. Or, release control is resumed. Thus, even if the failure flag is ON, since the operation continuation possible flag is ON, the operation can be resumed by an Apply request or a release request from the state where the electric motor 43B is stopped due to the abnormality detection. Apply control processing and release control processing are performed. In this case, since the operation continuation possible flag is ON, in the release control process (the process of FIG. 6), “YES” is determined in S36, and the operation can be resumed (continued) by proceeding to S34. it can. In addition, as needed, S52 can be provided between S35 and a return, for example, and an operation continuation possible flag can be turned off.

  On the other hand, if “NO” in S39, that is, if it is determined that the abnormality of the rotation / linear motion conversion mechanism 40 is (b) or (e), the operation continuation possible flag is set to ON without proceeding to S40. No), in S42, the fact that the state of the piston 39 by the rotation / linear motion converting mechanism 40 is in an unknown state is stored in the memory 24, and then the process proceeds to return. The process proceeds to the return of FIG. 4 via this return, and the process of S1 is repeated. In this case, that is, when the process proceeds from S39 (without proceeding to S40) (when the failure flag is ON and the operation continuation enable flag is OFF), it is determined “NO” in S2 and S3. Even if there is an operation request signal (apply request or release request), the apply control process and the release control process are not performed (the drive of the electric motor 43B is prohibited).

  As described above, in the embodiment, it is possible to suppress the operation (holding and releasing) of the parking brake from being excessively limited.

  That is, in the embodiment, when an abnormality of the rotation / linear motion converting mechanism 40 is detected by the process of S12 or S32, the driving of the electric motor 43B is stopped by the process of S18 or S38. However, when it is detected by the process of S19 or S39 that the operation of the rotation / linear motion conversion mechanism 40 can be continued, the operation continuation enable flag is turned ON in S20 or S40, and there is an operation request signal. Sometimes, the driving of the electric motor 43B is resumed by the processing of S3 and S11 or S3 and S31, and the driving of the electric motor 43B is continued by the processing of S16 or S36. For this reason, even if an abnormality in the rotation / linear motion conversion mechanism 40 is detected, if the operation of the rotation / linear motion conversion mechanism 40 can be continued, the operation continuation possible flag is turned on to stop the abnormality. The parking brake can be applied or released by a new apply operation or release operation. Thereby, it can suppress that the action | operation (a holding | maintenance, cancellation | release) of a parking brake is restrict | limited excessively. As a result, for example, when an abnormality is detected, compared to a configuration in which the driving of the electric motor is prohibited thereafter, the parking brake cannot be applied, or the vehicle is prevented from traveling with the parking brake applied. Can do.

  In the first embodiment, the processing of S12, S13, and S18 of FIG. 5 or the processing of S32, S33, and S38 of FIG. 6 shows a specific example of the abnormality detection means that is a constituent requirement of the present invention. Yes. Moreover, the process of S19 of FIG. 5 or the process of S39 of FIG. 6 has shown the specific example of the operation continuation possibility detection means which is a structural requirement of this invention. Furthermore, the process of S3 in FIG. 4 and the process in S20 in FIG. 5, or the process in S3 in FIG. 4 and the process in S40 in FIG. Yes.

  Next, FIG. 7 and FIG. 8 show a second embodiment. The feature of the second embodiment is that the operation resuming permission means is configured to resume the operation based on the operation request signal only for the operation request signal when an abnormality is detected after stopping by the abnormality determination. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In 2nd Embodiment, the operation resumption permission means of the parking brake control apparatus 22 is set as the structure which restarts the operation | movement based on the said operation request signal only for the operation request signal at the time of detecting abnormality. For this reason, when it is detected by the process of S19 or S39 that the operation of the rotation / linear motion conversion mechanism 40 can be continued, the operation continuation possible flag is not used, and the process of S23 or S43 is performed by the process of S23 or S43. Is resumed. Then, when the electric motor 43B is stopped by the processing of S25 or S45, the fact that the state of the piston 39 by the rotation / linear motion conversion mechanism 40 is unknown is stored in the memory 24 in S21 ′ or S41 ′, and then FIG. The process returns to the process.

  Also, as shown in FIG. 7, the apply control process of the second embodiment is configured to return to the process of FIG. 1 (via S22) when it is determined “NO” in S19. As shown in FIG. 8, in the release control process of the second embodiment, if “NO” is determined in S39, the process returns to the process of FIG. 1 (through S42).

  Here, in the second embodiment, in the flowchart of FIG. 4, the process of S3 is deleted, and if “NO” is determined in the process of S2, the process is changed to return. As a result, the operation when the abnormality that can continue the operation is detected is restarted. However, when the restarted operation is completed, the failure flag is turned ON in S17 or S37. The process determines “NO” and returns. As a result, after the abnormality is detected, even if there is an operation request signal (apply request or release request), the apply control process and the release control process are not performed (the drive of the electric motor 43B is prohibited).

  In the second embodiment, when the operation of the rotation / linear motion converting mechanism 40 can be continued by the apply control process and the release control process as described above, the driving of the electric motor 43B is resumed. There is no particular difference from that according to the first embodiment.

  In particular, in the second embodiment, the operation based on the operation request signal is resumed by the processing of S19 and S23 following the processing of S18 or S38, or the processing of S39 and S43. In addition, the resuming operation is performed only for the operation request signal when an abnormality that can continue the operation is detected by the processing of S17 and S2 or S37 and S2. For this reason, even if an abnormality of the rotation / linear motion conversion mechanism 40 is detected, if the operation of the rotation / linear motion conversion mechanism 40 can be continued, even if the operation is resumed, Subsequent operations are stopped. Thereby, in addition to being able to control that operation (holding, release) of a parking brake is restricted too much, it can control that an operation is repeated after an abnormality is detected.

  In the second embodiment, the processing of S12, S13, and S18 of FIG. 7 or the processing of S32, S33, and S38 of FIG. Yes. Moreover, the process of S19 of FIG. 7 or the process of S39 of FIG. 8 has shown the specific example of the operation continuation possibility detection means which is a structural requirement of this invention. Furthermore, the process of S23 (and S17, S19) in FIG. 7 or the process of S43 (and S37, S39) in FIG. 6 shows a specific example of the operation resuming permission means which is a constituent requirement of the present invention.

  In each of the above-described embodiments, when it is possible to continue the operation of the rotation / linear motion conversion mechanism 40 in both the apply control process and the release control process, the case where the drive of the electric motor 43B is resumed is taken as an example. Explained. However, the present invention is not limited to this, and only the Apply control process or the release control process may be restarted.

  In the first embodiment described above, when a new operation request is made after detecting an abnormality that can continue operation, the operation request is accepted any number of times. Only one operation request after detecting the above may be accepted.

  In the second embodiment described above, the operation based on the operation request is resumed only for one operation request after detecting an abnormality that can continue the operation, but the operation request is accepted any number of times. You may do it.

  In each of the above-described embodiments, the case where the detection of the abnormality of the rotation / linear motion conversion mechanism 40 that is the pressing member holding mechanism is performed based on the motor current value has been described as an example. However, the present invention is not limited to this, and an abnormality of the pressing member holding mechanism is detected by using, for example, a rotational position of the electric motor detected by using a position sensor, a rotation sensor, etc., a displacement of the pressing member holding mechanism, and an electric motor detected by a temperature sensor. It is good also as a structure detected using the temperature of this. That is, the abnormality of the pressing member holding mechanism can be detected from the change in the state quantity of the pressing member holding mechanism and the change in the state quantity of the electric motor.

  In each of the above-described embodiments, the abnormality of the rotation / linear motion conversion mechanism 40 is detected as described in the above (a) to (g), and (c), (d), and (g) among them are abnormal that can continue to operate. The case described above is described as an example. However, the present invention is not limited to this, and an abnormality other than the above (a) to (g) may be detected, or an abnormality that allows continued operation may be changed. That is, the detection of the abnormality of the pressing member holding mechanism and the detection of whether or not the operation can be continued vary depending on the configuration of the pressing member holding mechanism, the configuration of the brake mechanism, the configuration of the electric motor, these specifications, etc. Can be set.

  In each of the above-described embodiments, the case where the left and right rear wheel brakes are the disc brakes 31 with the 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 brakes may be disc brakes with an electric parking brake function. Moreover, you may comprise the brake of all the wheels (all four wheels) of a front wheel and a rear wheel by the disc brake with an electric parking brake function. That is, the brake of at least a pair of wheels of the vehicle can be configured by a disc brake with an electric parking brake function.

  In the above-described embodiments, the hydraulic disc brake 31 with the electric parking brake has been described as an example. However, the present invention is not limited to this, and an electric disc brake that does not require supply of hydraulic pressure may be used. Further, the present invention is not limited to the disc brake type brake device, and may be configured as a drum brake type brake device. Further, various brake mechanisms can be employed, such as a drum-in disc brake in which a drum-type electric parking brake is provided on the disc brake, and a configuration in which the parking brake is held by pulling a cable with an electric motor. In this case, for example, when an electric brake mechanism that does not require supply of hydraulic pressure is adopted, the control means applies a braking force to the vehicle as a service brake (based on an apply request by operating a brake pedal or the like) (A motor is driven).

  According to the above embodiment, it can suppress that the action | operation (a holding | maintenance, cancellation | release) of a parking brake is restrict | limited excessively.

  That is, according to the first embodiment, even if the abnormality detecting unit detects an abnormality of the pressing member holding mechanism and stops the operation of the pressing member holding mechanism, the operation of the pressing member holding mechanism is continued by the operation continuation possibility detecting unit. Is detected, the operation is permitted by the operation resuming permission means. For this reason, even if an abnormality of the pressing member holding mechanism is detected, if the operation of the pressing member holding mechanism can be continued, the operation is resumed in response to a new operation request after the abnormality is determined, so that the braking force Can be granted or released. Thereby, it can suppress that the action | operation (a holding | maintenance, cancellation | release) of a parking brake is restrict | limited excessively. As a result, for example, when an abnormality is detected, compared to a configuration in which the driving of the electric motor is prohibited thereafter, the parking brake cannot be applied, or the vehicle is prevented from traveling with the parking brake applied. Can do.

  According to the second embodiment, the operation resumption permitting unit is configured to resume the operation based on the operation request signal only for one operation request signal after detecting the abnormality. For this reason, even if an abnormality of the pressing member holding mechanism is detected, if the operation of the pressing member holding mechanism can be continued, even if the operation is resumed, when the resumed operation is completed, the subsequent operation is performed. Stopped. In this case, it is possible to suppress the operation (holding and release) of the parking brake from being excessively limited, and to suppress the operation from being repeated after an abnormality is detected.

1 Car body 2 Front wheel
3 Rear wheels
4 Disc rotor (rotating member)
6 Brake pedal 22 Parking brake control device (control means, abnormality detection means, operation continuity detection means, operation resumption permission means)
33 Brake pads (friction members)
34 Caliper (brake mechanism)
39 Piston (Pressing member)
40 Rotational linear motion conversion mechanism (pressing member holding mechanism)
43B Electric motor

Claims (3)

A brake mechanism for propelling a friction member, which is disposed so as to come into contact with each rotating member rotating with at least a pair of wheels of the vehicle, by a pressing member based on an operation of a brake pedal;
A pressing member holding mechanism for propelling the pressing member of each brake mechanism by an electric motor and holding the pushed pressing member;
Control means for switching whether or not the electric motor can be controlled with respect to the operation request signal, and storing a pressing member holding state or a releasing state by the pressing member holding mechanism upon completion of the operation according to the operation request signal,
The control means includes
An abnormality detecting means for detecting an abnormality of the pressing member holding mechanism according to a situation within a predetermined time at the time of operation according to the operation request signal and stopping the operation of the pressing member holding mechanism;
An operation for detecting whether or not the operation of the pressing member holding mechanism can be continued from the contents of the control to the electric motor when the abnormality is detected by the abnormality detection unit when an abnormality is detected by the abnormality detection unit. Continuity detection means;
An operation resumption permitting unit that allows the operation of the pressing member holding mechanism to be resumed when the operation continuation possibility detecting unit detects that the operation of the pressing member holding mechanism can be continued. Brake device.   2. The brake device according to claim 1, wherein the operation restart permitting unit restarts the operation based on the operation request signal in accordance with the operation request signal after the abnormality is detected by the abnormality detection unit.   The operation continuation enable / disable detection means detects whether or not the operation of the pressing member holding mechanism can be continued from a current value supplied to the electric motor as a control content to the electric motor and a supply time of the current value. Item 4. The brake device according to item 1.

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