Electric brake device

Abstract

The control device (2) of the electric brake device includes first, second and third PKB actuators. When the first PKB actuator (24aa) receives an indication of being in a parking brake state during the parking brake release, it exerts a braking force independently of a brake command mechanism (Bp) and determines that it is in a state where a desired braking force is exerted. After the judgment of the first PKB actuator (24aa), the second PKB actuator (24ab) is in a state where the movable part (15) is engaged with the engaged part (Hk), and the electric motor (4) is rotated in a direction of reducing the braking force, thereby being in a state where the engaged part (Hk) and the movable part (15) are engaged and the rotation of the electric motor (4) is blocked. Thereafter, the third PKB actuator (24ac) is in a parking brake state where the electric motor (4) is not generated with driving power.

Description

[0001] Related Applications

[0002] This application claims the benefit of priority from Japanese Patent Application No. 2019-115520, filed on June 21, 2019, the entirety of which is incorporated herein by reference as a part of this application. Technical Field

[0003] The present invention relates to an electric brake device mounted on a vehicle or the like. Background Art

[0004] The following techniques have been proposed as electric brake devices.

[0005] 1. An electric brake with a parking brake function, in which a locking mechanism is provided on the outer periphery of a ratchet wheel (Patent Document 1).

[0006] 2. An electric actuator using a planetary roller mechanism and an electric motor (Patent Document 2).

[0007] Prior art literature

[0008] Patent Literature

[0009] Patent Document 1: Japanese Patent Application Publication No. 2006-183809

[0010] Patent Document 2: Japanese Patent Application Publication No. 2006-194356 Summary of the invention

[0011] Problems to be solved by the invention

[0012] For example, as in the parking brake mechanism in the electric brake device of Patent Documents 1 and 2, there is a case where an electric actuator is required that can lock while maintaining a predetermined load state without relying on the electric power of a motor.

[0013] At this time, for an electric actuator having a reverse input holding mechanism formed by engaging a movable part with a stationary part as in Patent Document 1, when transferring to a reverse input holding state and releasing the reverse input holding state, it is often required to reliably perform these state transfers. For example, if a reverse input holding mechanism is applied to a parking brake function part of an electric brake device using an electric actuator, if the transfer to the reverse input holding state, i.e., the parking brake state, fails, there is a problem that the vehicle moves on a slope against the operator's intention, and if the parking brake release fails, there is a problem that the vehicle cannot start.

[0014] An object of the present invention is to provide an electric brake device which has less malfunction and can perform accurate parking brake operation.

[0015] Technical solutions to solve problems

[0016] The electric brake device 1 of the present invention comprises: a brake rotor 8; a friction member 9, which abuts against the brake rotor 8 to generate a braking force; an electric motor 4; a friction member operating mechanism 6, which operates the friction member 9 through the electric motor 4; a control device 2, which has a control operator 23 that calculates an electric motor operation amount, and the electric motor operation amount is used to make the braking force follow: a target braking force provided by a drive circuit 18 that drives the electric motor 4 and a brake command mechanism Bp;

[0017] The electric brake device 1 comprises:

[0018] a parking brake mechanism 7, the parking brake mechanism 7 having an engaged portion Hk and a movable portion 15, the engaged portion Hk moving synchronously with the rotation of the electric motor 4, the movable portion 15 being movable in engagement and disengagement with respect to the engaged portion Hk, and by engaging the movable portion 15 with the engaged portion Hk, the movement synchronous with the rotation of the electric motor 4 is hindered, and the braking force generated by the contact between the brake rotor 8 and the friction member 9 is maintained independently of the driving force of the electric motor 4;

[0019] a parking brake command mechanism Ps, which sends an instruction to the control device 2 as to whether to adopt the parking brake mechanism 7 to form the following parking brake state, in which the braking force does not follow the command value of the brake command mechanism Bp but maintains the determined braking force;

[0020] The control device 2 includes: a braking force estimation mechanism 21, which estimates the braking force; a motor motion estimation mechanism 22, which estimates the electric motor motion state, which at least includes the angle of the electric motor 4 or the calculus value of the angle, or any one of the motion amounts equivalent to the angle or the calculus value of the angle;

[0021] The control device 2 comprises:

[0022] a first parking brake operating unit 24aa which, when receiving an instruction of being in the parking brake state through the parking brake command unit Ps during the parking brake release which is not the parking brake state, exerts the braking force independently of the brake command unit Bp and determines that a braking force exceeding the braking force to be exerted in the parking brake state is exerted based on at least the braking force estimating unit 21;

[0023] a second parking brake actuating unit 24ab, which, after the judgment of the first parking brake actuating unit 24aa, is in a state of engaging the movable unit 15 with the engaged unit Hk, and at least according to the motor motion estimation mechanism 22, rotates the electric motor 4 in the direction of reducing the braking force, thereby engaging the engaged unit Hk and the movable unit 15 to hinder the rotation of the electric motor 4;

[0024] The third parking brake operating unit 24ac is configured to be in a parking brake state in which the electric motor 4 is not caused to generate driving power after the second parking brake operating unit 24ab is executed.

[0025] The above-determined braking force is a braking force arbitrarily determined by design or the like, and is determined by obtaining an appropriate braking force through, for example, one or both of tests and simulations.

[0026] According to this aspect, the control device 2 performs a follow-up control on the braking force relative to the target braking force provided by the brake command means Bp during the parking brake release.

[0027] When the parking brake command unit Ps sends an instruction to the control device 2 to enter the parking brake state, the first parking brake actuator 24aa, the second parking brake actuator 24ab, and the third parking brake actuator 24ac are controlled in sequence.

[0028] First, when the first parking brake actuator 24aa receives an instruction to enter the parking brake state during parking brake release, it exerts a braking force independently of the brake command mechanism Bp. The first parking brake actuator 24aa further determines that a braking force exceeding the braking force that should be exerted in the parking brake state is exerted.

[0029] After this determination, the second parking brake actuator 24ab engages the movable portion 15 with the engaged portion Hk, and rotates the electric motor 4 in a direction to reduce the braking force. Thus, the engaged portion Hk and the movable portion 15 are engaged in a so-called locked state.

[0030] Thereafter, the third parking brake actuator 24ac is in a parking brake state in which the electric motor 4 is not caused to generate drive power.

[0031] When the vehicle is shifted to the parking brake state as described above, the vehicle sequentially performs the actions of exerting a braking force equivalent to the parking brake, locking the parking brake mechanism 7, and suppressing the power consumption of the electric motor 4 while maintaining the parking brake state. This reduces erroneous operations and enables correct parking brake operation.

[0032] The control device 2 may also include:

[0033] a first parking brake releasing action unit 24ba, which, in the parking brake state, is in a state where the movable part 15 is disengaged from the engaged part Hk when receiving an instruction to release the parking brake state through the parking brake command mechanism Ps, and, based on at least one or both of the braking force estimation mechanism 21 and the motor motion estimation mechanism 22, rotates the electric motor 4 in the braking force boosting direction from the state where the parking brake release is started, so that the rotation state of the electric motor 4 is in a state where the movable part 15 can be disengaged;

[0034] The second parking brake releasing action unit 24bb, after the execution of the first parking brake releasing action unit 24ba, the second parking brake releasing action unit 24bb rotates the above-mentioned electric motor 4 based on at least one or both of the above-mentioned braking force estimation mechanism 21 and the above-mentioned electric motor motion estimation mechanism 22, and determines that the parking brake release has been completed based on the situation that the rotation amount of the electric motor exceeds the specified amount.

[0035] The predetermined amount is an amount arbitrarily determined by design or the like, and is determined by obtaining an appropriate amount through, for example, one or both of experiments and simulations.

[0036] In this case, by sequentially rotating the electric motor 4 toward the pressure-increasing side to disengage the movable portion 15 from the engaged portion Hk and reducing the pressure to release the parking brake load from the parking brake state, accurate parking brake release operation with little malfunction can be performed.

[0037] The control device 2 may also, during the execution of the first parking brake action unit 24aa, when receiving an instruction to release the parking brake state through the parking brake command mechanism Ps, perform follow-up control on the braking force relative to the target braking force provided by the braking command mechanism Bp, without relying on the braking force exerted by the braking command mechanism Bp.

[0038] During the execution of the first parking brake actuating portion 24aa, the movable portion 15 is not engaged with the engaged portion Hk. Therefore, when the control device 2 receives an instruction to release the parking brake state, it quickly switches to the service brake, thereby also being able to cope with emergency parking brake release caused by erroneous operation.

[0039] The control device 2 has a function of estimating the external disturbance torque acting on the electric motor 4 based on at least the motor motion estimation mechanism 22;

[0040] The control device 2 may also, during the execution of the second parking brake action unit 24ab, determine that the rotation of the electric motor 4 is hindered due to the engagement of the parking brake mechanism 7 when an external interference torque greater than a torque determined in a direction corresponding to the brake boost direction is calculated.

[0041] In this way, the determination of the completion of the locking action can be specifically performed.

[0042] The above-mentioned determined torque is a torque arbitrarily determined by design or the like, and is determined by obtaining an appropriate torque through, for example, one or both of tests and simulations.

[0043] The control device 2 may also have a function of estimating the current of the electric motor 4. During the execution of the second parking brake action unit 24ab, when the control device 2 estimates a current greater than a determined current that generates a torque in a direction corresponding to the direction of brake decompression, the control device 2 determines that the rotation of the electric motor 4 is hindered due to the engagement of the parking brake mechanism 7.

[0044] In this way, the determination of the completion of the locking action can be specifically performed.

[0045] The above-determined current is a current arbitrarily determined by design or the like, and is determined by finding an appropriate current through, for example, one or both of experiments and simulations.

[0046] The engaged portion Hk and the movable portion 15 may also have an engagement interval, and the engagement interval is a positional relationship that allows engagement whenever the electric motor 4 rotates a predetermined angle.

[0047] During the execution of the second parking brake action unit 24ab, the control device 2 determines that the engagement of the parking brake mechanism 7 has failed when the electric motor 4 rotates beyond the engagement interval, at least based on the motor motion estimation mechanism 22, and executes the first parking brake action and the second parking brake action more than once.

[0048] The determined angle is an angle arbitrarily determined by design or the like, and is determined by finding an appropriate angle through, for example, one or both of experiments and simulations.

[0049] For example, when the parking brake mechanism is not used for a long time, the operation speed of the movable part 15 of the parking brake mechanism may be slowed down due to the mixing of wear powder or grease of the peripheral parts of the parking brake mechanism. In such a case, by setting the locking operation of the parking brake mechanism 7 to be repeatedly performed up to a certain number of times, the reliability of the parking brake operation can be improved.

[0050] The control device 2 may also determine, during the execution of the second parking brake release action unit 24bb, that the rotation of the electric motor 4 is obstructed by the parking brake mechanism 7, at least based on the motor motion estimation mechanism 22, and when the rotation of the electric motor 4 is obstructed, determine that the parking brake release has failed, and execute the first parking brake release action unit 24ba more than once.

[0051] When the operating speed of the movable portion 15 of the parking brake mechanism 7 slows down, the reliability of the parking brake release operation can be improved by repeating the release operation as the lock release operation of the parking brake mechanism 7 up to a certain number of times.

[0052] Any combination of at least two structures disclosed in the claims and / or the specification and / or the drawings is also included in the present invention. In particular, any combination of two or more of the claims of the claims is also included in the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention can be more clearly understood from the following description of preferred embodiments with reference to the accompanying drawings. However, the embodiments and the accompanying drawings are only for illustration and description and should not be used to limit the scope of the present invention. The scope of the present invention is determined by the claims. In the accompanying drawings, the same reference numerals in multiple drawings represent the same or equivalent parts.

[0054] Figure 1 It is a diagram schematically showing an electric brake device according to a first embodiment of the present invention.

[0055] Figure 2 A diagram showing a structural example of an engaged portion of a parking brake mechanism in the electric brake device;

[0056] Figure 3 A diagram schematically showing a state in which the movable portion is engaged with or disengaged from the engaged portion;

[0057] Figure 4 A block diagram of a control system of the electric brake device;

[0058] Figure 5 is a flow chart showing the basic operation of the parking brake controller;

[0059] Figure 6 For about Figure 5 A flowchart of the locking action recorded in S5;

[0060] Figure 7 For about Figure 5 A flowchart of the release action recorded in S10;

[0061] Figure 8 A diagram showing state transition of the parking brake controller;

[0062] Fig. 9 A diagram showing an example of the operation of the parking brake mechanism;

[0063] Fig.10 A block diagram of a control system of an electric brake device according to another embodiment of the present invention;

[0064] Fig.11 A diagram showing another structural example of the engaged portion;

[0065] Fig.12 A diagram showing another structural example of the engaged portion;

[0066] Fig.13 A diagram showing another structural example of the engaged portion;

[0067] Fig.14 A diagram showing yet another structural example of the engaged portion;

[0068] Fig.15 It is a figure which shows still another structural example of the engaged part. DETAILED DESCRIPTION

[0069] [First embodiment]

[0070] according to Figures 1 to 9 The electric brake device according to the embodiment of the present invention is described below. The electric brake device is mounted on a vehicle, for example.

[0071] picture Figure 1 As shown, the electric brake device 1 includes a brake actuator BA, a power supply device 3, and a control device 2. First, the structure of the brake actuator BA will be described.

[0072] <Configuration Example of Brake Actuator BA>

[0073] The brake actuator BA includes an electric motor 4, a linear motion mechanism 6, a speed reducer 5, a friction brake BR, a parking brake mechanism 7, an angle sensor Sa ( Figure 4 ) and load sensor Sb( Figure 4 ).

[0074] The electric motor 4 includes a rotor and a stator, and is constituted by, for example, a permanent magnet synchronous electric motor. If the electric motor 4 is a permanent magnet synchronous electric motor, it is preferred because it saves space, has high efficiency and high torque.

[0075] The friction brake BR is provided on each wheel of the vehicle. The friction brake BR includes a brake rotor 8 that rotates in conjunction with the wheel, and a friction member 9 that abuts against the brake rotor 8 to generate a braking force. The friction member 9 can be operated by a linear motion mechanism 6 as a friction member operating mechanism, and pressed against the brake rotor 8, and a load is generated by friction force. As the friction brake BR of this example, a disc brake device using a brake rotor 8 as a brake disc and a caliper not shown in the figure is adopted, but a drum brake device using a drum and a lining may also be adopted.

[0076] The speed reducer 5 is a mechanism for reducing the rotation of the electric motor 4, and includes a primary gear 12, an intermediate gear 13, and a tertiary gear 11 as transmission parts. In this example, the speed reducer 5 uses parallel gears, which reduce the rotation of the primary gear 12 mounted on the rotor shaft 4a of the electric motor 4 through the first and second gear shape parts 13a and 13b of the intermediate gear 13, and can be transmitted to the tertiary gear 11 fixed to the end of the rotating shaft 10.

[0077] The linear motion mechanism 6 is a mechanism that converts the rotational motion output by the speed reducer 5 into the linear motion of the linear motion part 14 through the feed screw mechanism, so that the friction member 9 abuts against or separates from the brake rotor 8. The linear motion part 14 is stopped and supported to be freely movable in the axial direction indicated by the arrow A1. The friction member 9 is provided at the outer end of the linear motion part 14. By transmitting the rotation of the electric motor 4 to the linear motion mechanism 6 via the speed reducer 5, the rotational motion is converted into the linear motion, which is converted into the pressing force of the friction member 9, thereby generating a braking force. In addition, when the electric brake device 1 is mounted on the vehicle, the outer side of the vehicle in the vehicle width direction is referred to as the outer side, and the central side of the vehicle in the vehicle width direction is referred to as the inner side.

[0078] picture Figure 4 As shown in FIG. 1 , the angle sensor Sa detects the rotation angle (motor angle) as the rotation amount of the electric motor 4. For example, if a resolver or a magnetic encoder is used as the angle sensor Sa, it is preferably used because it has high accuracy and high reliability, but various sensors such as an optical encoder may also be used. Instead of using the angle sensor Sa, the control device 2 described later may use an angle sensorless estimation method that estimates the angle of the electric motor 4 based on the relationship between the voltage and current of the electric motor 4.

[0079] The load sensor Sb detects the axial load of the linear motion mechanism 6. If the load sensor Sb adopts a sensor that detects strain or deformation corresponding to the load of the linear motion mechanism 6, it is inexpensive and highly accurate, which is preferable. The load sensor Sb may also adopt a pressure-sensitive medium such as a piezoelectric element, a torque sensor that detects the braking torque of the brake rotor 8, or an acceleration sensor that detects the front and rear deceleration of the vehicle in the case of the electric brake device 1 for a vehicle. Alternatively, in the control device 2, it is also possible to perform sensorless estimation without providing a load sensor based on a prescribed correlation such as the correlation between the actuator stiffness and the motor angle, the correlation between the actuator load and the motor torque, etc.

[0080] <Structural Example of Parking Brake Mechanism>

[0081] picture Figure 1 and Figure 2 As shown, the parking brake mechanism 7 is a mechanism for maintaining the braking force of the brake rotor 8 and the friction member 9 in contact with each other independently of the driving force of the electric motor 4. The parking brake mechanism 7 has an engaged portion Hk that moves synchronously with the rotation of the electric motor 4, and a solenoid 16 as a driving source, which drives the movable portion 15 in a manner that enables engagement / disengagement with respect to each hole ha of the engaged portion Hk.

[0082] In this example, the intermediate gear 13 of the speed reducer 5 is used as the engaged portion Hk, and a plurality of (six in this example) holes ha are evenly provided on the circumference of the end surface in the rotation axis direction of the intermediate gear 13 .

[0083] Figure 2 (a) is a front view of the intermediate gear 13, Figure 2 (b) is along Figure 2 The cross-sectional view along the line II(b)-II(b) in (a) is shown in FIG. Figure 2 (c) is along Figure 2 The cross-sectional view of line II(c)-II(c) in (a). Figure 2 As shown in (a) to (c) of FIG. 1 , each of the holes ha is a through hole that penetrates the first gear shape portion 13a of the intermediate gear 13 in the axial direction and is a long hole that extends in an arc shape with a predetermined length in the circumferential direction.

[0084] like Figure 2 and Figure 3 As shown, when the parking brake mechanism 7 is locked by using this structure, the movable portion 15 as the locking pin protrudes from the solenoid 16 which is held by a stationary system such as a housing and faces the solenoid 16, and is engaged with any of the above-mentioned holes ha, thereby preventing the electric motor 4 ( Figure 1 ) rotates, and the engagement state is maintained by the friction force of the contact surface between the engaged portion Hk and the movable portion 15. Figure 1 ) maintains the locked state of the parking brake mechanism 7 regardless of the driving force of the electric motor 4 ( Figure 1 ) is a positional relationship that allows engagement when the components are rotated a certain angle.

[0085] like Figure 1 and Figure 2 As shown, the solenoid 16 generates an excitation magnetic field by means of a solenoid coil, and drives the movable portion 15 as a locking pin by means of an electromagnetic force, and the movable portion 15 is engaged with the hole ha of the engaged portion Hk of the opposing reducer 5, thereby locking the rotation of the intermediate gear 13 linked to the electric motor 4, thereby placing the parking brake mechanism 7 in a locked state. By disengaging the movable portion 15 from the hole ha of the engaged portion Hk, the rotation of the intermediate gear 13 is allowed, and the parking brake mechanism 7 is in a locked state (released state).

[0086] In this structure, a biasing mechanism such as a spring (not shown) is provided in the solenoid 16 to keep the movable part 15 in a state separated from the engaged part Hk, and a structure in which an electromagnetic force exceeding the force of the above-mentioned force-applying mechanism is generated by energizing the solenoid 16 to become a lockable state is inexpensive and power-saving, which is preferred. However, the solenoid 16 may also be configured as follows: an excitation part such as a magnet is provided in the movable part 15 as a locking pin, and the movable part 15 is bidirectionally driven according to the direction of the current of the solenoid coil.

[0087] A structure for locking the engaged portion Hk by providing a DC motor and a screw mechanism may be formed instead of the solenoid 16. In addition, the engaged portion Hk is preferably provided in the reducer 5 to save space, but it may be provided in any part such as the rotor of the electric motor 4 or the linear motion mechanism 6 that operates in conjunction with the rotation of the motor.

[0088] In addition, various sensors such as a thermistor may be provided separately as elements not shown in the figure according to necessary conditions.

[0089] <Structure of control device>

[0090] Figure 4This is a block diagram of the control system of the electric brake device 1. For example, a control device 2 and a brake actuator BA corresponding to each wheel are provided. Each control device 2 controls the corresponding electric motor 4. A DC power supply device 3, a brake pedal Bp as a brake command mechanism, and a parking brake switch Ps as a parking brake command mechanism are connected to each control device 2. For example, in the electric brake device 1 for automobiles, the power supply device 3 may adopt a buck converter that steps down a low-voltage (such as 12V) battery or a high-voltage battery. Alternatively, the power supply device 3 may also use high-capacity capacitors, or use them in parallel for redundancy processing.

[0091] The brake pedal Bp provides the output of the sensor that changes according to the amount of operation by the operator as a brake command signal (target braking force) to each control device 2. In addition, the brake command mechanism can also be various operating mechanisms that can be operated by the operator, such as a volume, a joystick, a switch, etc. In addition, the brake command mechanism can also automatically obtain and output a command value (brake command signal) based on the state of the vehicle and information from various sensors, etc., without relying on the operation of the operating mechanism, such as an automatic driving vehicle.

[0092] The parking brake switch Ps is a switch operable by the operator, and sends an instruction to the control device 2 as to whether to use the parking brake mechanism 7 to maintain a predetermined braking force without the braking force following the braking command signal of the brake pedal Bp.

[0093] Each control device 2 includes various control computing units for performing control computing, a motor driver 18 , an electromagnetic driver 19 , and a current sensor 20 . The various control computing units include a braking force estimation mechanism 21 , a motion state estimation unit 22 , a control computing unit 23 , and a parking brake controller 24 .

[0094] The braking force estimating means 21 estimates the braking force as the load acting on the outside by the brake actuator BA based on the output of the load sensor Sb. In addition, the braking force estimating means 21 may perform sensorless estimation without using the load sensor Sb as described above.

[0095] The motion state estimator 22 as a motor motion estimating mechanism estimates the rotational motion state of the electric motor 4 based on the output of the angle sensor Sa. The motion state estimator 22 includes an angle estimating unit 22a for estimating the angle (rotation angle) of the rotor of the electric motor 4, and an angular velocity estimating unit 22b for estimating the angular velocity of the electric motor 4. Alternatively, the motion state estimator 22 may also be provided with a function of estimating a predetermined calculus value of the angular acceleration of the electric motor 4, a function of estimating external disturbance, and the like.

[0096] The angle estimation unit 22a has a function of appropriately obtaining necessary physical quantities when estimating the rotation angle of the electric motor 4, such as the electrical angle phase for current control or the total rotation angle for compensating overlap and under-overlap of the angle sensor Sa for angle control. In addition, the rotation angle and angular velocity may be replaced by the rotor of the electric motor 4, such as the angle of a predetermined portion of the reducer 5 obtained from the reduction ratio, or the position and velocity obtained from the equivalent lead. The calculation of the physical quantities may be performed by a structure such as a state estimation observer, or by direct calculation such as differential or inverse calculation of the inertia equation.

[0097] The current sensor 20 may be, for example, a sensor composed of an amplifier that detects the voltage across a shunt resistor, or a non-contact sensor that detects the magnetic flux around the current path of the phase current of the electric motor 4. As another structure, the current sensor 20 may be, for example, a structure that detects the terminal voltage of a component constituting the motor driver 18. In addition, the current sensor 20 may be arranged between phases of the electric motor, or one or more may be arranged on the low side or the high side. Alternatively, the control device 2 may not be provided with any current sensor, but may perform feedforward control based on the electric motor characteristics such as the inductance or resistance value of the electric motor 4.

[0098] The control operator 23 as an actuator controller calculates the operation amount (electric motor operation amount) for making the braking force follow the braking command signal provided from the brake pedal Bp. That is, the control operator 23 has the following function: to find the operation amount for making the brake actuator BA ideally follow the specified command input, and convert it into a motor drive signal. The control operator 23 mainly includes a brake load control unit 23a for controlling the braking load (braking force) and a motor angle control unit 23b for controlling the electric motor angle, and the brake load control unit 23a and the motor angle control unit 23b are switched according to the necessary conditions. In addition, as a function not shown in the figure, if a current controller for controlling the motor current and a function of deriving the motor current for exerting the desired motor torque based on the motor output characteristics are provided in the control operator 23, high-function control can be performed, which is preferred.

[0099] The parking brake controller 24 has a control operation function for making the electric motor 4 and the solenoid 16 cooperate to transfer to the parking brake state and release the parking brake state. The parking brake controller 24 has a lock control unit 24a for transferring to the parking brake state and a release control unit 24b for releasing the parking brake state. A control switching signal for switching the lock control unit 24a and the release control unit 24b is output from the parking brake controller 24 to the control operator 23.

[0100] In the parking brake state, the engaged portion Hk is locked by the movable portion 15 of the solenoid 16 as a locking pin, etc., and the locked state is maintained by the friction force generated by the reverse input acting on the contact portion of the engaged portion Hk, so that the electric motor 4 does not generate driving power (in other words, does not consume motor power). At this time, the electric motor 4 may be in a disabled state where power is stopped, or in a state where control is continuously executed by power saving such as zero torque, or a combination thereof.

[0101] The locking control unit 24a includes a first parking brake (PKB) actuator 24aa, a second parking brake (PKB) actuator 24ab, and a third parking brake actuator (PKB) 24ac. When the first PKB actuator 24aa receives an indication of being in the parking brake state through the parking brake switch Ps during the parking brake release that is not in the parking brake state, the braking force is exerted independently of the brake pedal Bp, and at least based on the braking force estimation mechanism 21, it is judged that the braking force that exceeds the braking force that should be exerted in the parking brake state is exerted.

[0102] After the judgment of the first PKB action part 24aa, the second PKB action part 24ab is in a state of engaging the movable part 15 with the engaged part Hk, and at least according to the motion state estimator 22, the electric motor 4 is rotated in the direction of reducing the braking force, thereby being in a state where the engaged part Hk and the movable part 15 are engaged and the rotation of the electric motor 4 is hindered.

[0103] After the second PKB actuation unit 24ab is executed, the third PKB actuation unit 24ac is in a parking brake state in which the electric motor 4 is not allowed to generate drive power.

[0104] Basically, they are executed in the order of the first PKB actuator 24aa, the second PKB actuator 24ab, and the third PKB actuator 24ac. The state in which the execution of the third PKB actuator 24ac is normally completed is the parking brake state.

[0105] The release control unit 24b includes a first parking brake (PKB) release action unit 24ba and a second parking brake (PKB) release action unit 24bb. When the first PKB release action unit 24ba receives an instruction to release the parking brake state through the parking brake switch Ps in the parking brake state, the movable part 15 is in a state of being disengaged from the engaged part Hk, and the electric motor 4 is rotated in the direction of increasing the braking force from the state where the parking brake release is started, based on at least one or both of the braking force estimation mechanism 21 and the motion state estimation unit 22, and the rotation state of the electric motor 4 is set to a state where the movable part 15 can be disengaged. That is, the first PKB release action unit 24ba rotates the electric motor 4 by a predetermined amount in a manner that the braking load increases compared to the parking brake state, and sets the movable part 15 as a locking pin to a state where it can be disengaged from the engaged part Hk.

[0106] After executing the first PKB release operation unit 24ba, the second PKB release operation unit 24bb rotates the electric motor 4 based on at least one or both of the braking force estimation mechanism 21 and the motion state estimation unit 22, and determines that the parking brake release is completed based on the rotation amount of the electric motor 4 exceeding the predetermined amount. That is, the second PKB release operation unit 24bb rotates the electric motor 4 by the predetermined amount so that the braking load is at least reduced compared to the parking brake state.

[0107] Basically, they are executed in the order of the first PKB release operation unit 24ba and the second PKB release operation unit 24bb. The state in which the execution of the second PKB release operation unit 24bb is normally completed is the parking brake release state, that is, the service brake state.

[0108] The various calculation functions described above are preferably constructed by a calculation unit such as a microcomputer, FPGA, or ASIC and peripheral circuits because they are inexpensive and have high performance.

[0109] The motor driver 18 controls the power supplied to the electric motor 4. If the electric motor driver 18 as a drive circuit is configured as a half-bridge circuit using a switching element such as a field effect transistor (FET), and is configured to perform PWM control that determines the motor applied voltage according to the ON-OFF duty ratio of the switching element, it is inexpensive and has high performance. Alternatively, a configuration may be configured to perform PAM control by providing a transformer circuit or the like.

[0110] The solenoid driver 19 drives and controls the solenoid 16 according to the solenoid on / off signal provided by the parking brake controller 24. It is preferable that the solenoid driver 19 is inexpensive when it is composed of a switching element such as a field effect transistor or a bipolar transistor. In the case of a solenoid 16 with a separation spring, the above-mentioned switching element can be provided as a switch that connects / disconnects the power supply device 3 to the solenoid 16, or a switch that connects / disconnects the power supply from the solenoid 16 to the GND, but a structure in which both are provided for redundancy can also be provided. In the case of a bidirectionally driven solenoid or a DC motor, a bridge circuit having at least four switching elements can also be formed.

[0111] As an element not shown in the figure, it is preferred to directly supply power from the power supply device 3 to the motor driver 18 or the solenoid driver 19. In the above-mentioned various control operators, a small buck converter structure is applied in the control device 2, but it can also be a structure that supplies power to either or both of the motor driver 18 and the solenoid driver 19 via a boost converter.

[0112] <Basic Operation Flow of the Parking Brake Controller 24>

[0113] Figure 5 2 is a flowchart showing the basic operation of the parking brake controller 24. Figure 4 For explanation.

[0114] After the process starts, the parking brake controller 24 determines the operating state of the parking brake (step S1). In step S1, when it is determined that the parking brake is released, that is, the service brake is in progress, the parking brake controller 24 determines whether the parking brake command is a parking brake operation request or a parking brake release request (step S2).

[0115] As the parking brake action request, for example, when the parking brake switch Ps is ON, it can be set as a parking brake action request, and when the parking brake switch Ps is OFF, it can be set as a parking brake release request. Alternatively, a switch with three or more states (for example, ON1-ON2-OFF switching) can be used, and when the parking brake switch Ps is ON1, a parking brake action request is made, when the parking brake switch Ps is ON2, a parking brake release request is made, and when the parking brake switch Ps is OFF, the above states are maintained. This is also the case when a command signal from a higher-level ECU is used as a parking brake command mechanism.

[0116] If the request is for releasing the parking brake in step S2, the vehicle is in the service brake state (step S3). If the request is for actuating the parking brake in step S2, the vehicle is shifted to the locking actuation state of the parking brake (step S4).

[0117] If it is determined in step S1 that the locking operation is in progress, the parking brake locking operation is performed (step S5). Next, the parking brake controller 24 determines whether the parking brake locking operation is completed (step S6), and if completed, shifts to the parking brake state (step S7).

[0118] In step S1, when it is determined that the parking brake state is in progress, the parking brake controller 24 determines whether the parking brake command is a parking brake actuation request or a parking brake release request (step S8). In the case of a parking brake release request, the electric motor 4 in a predetermined standby state is started to be driven during the parking brake (step S26), and the state is transferred to the release actuation state (step S9).

[0119] If it is determined in step S1 that the release operation is in progress, the release operation is performed (step S10). The parking brake controller 24 determines whether the release operation is completed (step S11), and if the release operation is completed, the state is shifted to the service brake state (step S12).

[0120] <Lock operation flow>

[0121] Figure 6 For about Figure 5 A flowchart of the locking action recorded in S5.

[0122] After the process starts, the locking control unit 24a determines whether the process execution state is the first execution (step S13). If it is the first execution, the current operation state is initialized to the first PKB operation state (step S14). The above-mentioned first execution means that the parking brake locking action changes from the non-operating state to the operating state for the first time.

[0123] Next, the parking brake locking operation state is determined (step S15). In the case of the first PKB operation state, the braking load is increased by the first PKB operation unit 24aa (step S16). Next, it is determined whether a predetermined braking load has been reached (step S17). If the predetermined braking load has been reached (step S17: yes), the state is transferred to the second PKB operation state (step S18). The predetermined braking load is preferably set to the parking brake load as the target plus the engagement spacing Pc ( Figure 3 ) etc. and the braking load is obtained by adjusting the offset amount that affects the holding load accuracy.

[0124] When it is determined in step S15 that the second PKB actuation state is in progress, the second PKB actuation unit 24ab drives the solenoid 16 to cause the movable portion 15 to protrude (step S19). Figure 6 The example using the solenoid 16 is shown, but even in the case of using a DC motor, the operation of driving the movable part 15 equivalent to the locking pin in a manner close to the engaged part Hk is the same. In addition, in the case where the protrusion time of the movable part 15 cannot be ignored, a predetermined standby time can also be set in the state of driving the solenoid 16.

[0125] The second PKB action unit 24ab rotates the electric motor 4 in the decompression direction while driving the solenoid 16 (step S20). The electric motor 4 may be rotated by braking load control, motor angle control, motor angular velocity control, etc., or the motor current may be slowly reduced and the motor may be rotated by the braking reaction force. Next, the locking control unit 24a determines whether the locking is completed (step S21). If the locking is completed (step S21: yes), the driving of the solenoid 16 is stopped (step S22), and the state is transferred to the third PKB action state (step S23).

[0126] Regarding the judgment of the completion of the above-mentioned locking, if the electric motor 4 is rotated in step S20, when the phases of the locking pin and the hole are roughly consistent, the locking pin and the hole are engaged, and then, the gap of the engaged portion Hk disappears relative to the rotation direction, and it can be judged that the rotation of the electric motor 4 is hindered. For example, in the case where an external disturbance observer is set, the judgment can be made based on the direction or size of the estimated external disturbance. Specifically, the locking control unit 24a has a function of estimating the external disturbance torque acting on the electric motor 4 based on at least the motion state estimator 22. When the locking control unit 24a estimates the above-mentioned external disturbance torque during the execution of the second parking brake action unit 24ab, when the external disturbance torque greater than the torque determined in the direction equivalent to the brake boost direction is estimated, it is judged that the rotation of the electric motor 4 is hindered due to the engagement of the parking brake mechanism 7.

[0127] As another judgment of whether the locking is completed, for example, in step S20, when the electric motor 4 is rotated by motor angle control or angular velocity control, a judgment can be made by detecting that a relatively large motor current is generated in the decompression direction. Specifically, when the current of the electric motor 4 is calculated to be larger than a certain current that generates torque in the direction corresponding to the braking decompression direction, the locking control unit 24a judges that the rotation of the electric motor 4 is hindered due to the engagement of the parking brake mechanism 7 during the execution of the second PKB action unit 24ab. In addition, for example, in step S20, when the electric motor current is reduced and the electric motor rotates by the braking reaction force, a judgment can be made by detecting that the rotation of the electric motor 4 has stopped.

[0128] In addition, the hole ha of the engaged portion Hk is Figure 2 In the case of a shape that can constrain the rotation of the motor in the phase direction, such as (a), the electric motor 4 can also be rotated in the supercharging direction in step S20. In this case, when the electric motor 4 rotates in the supercharging side, when the phases of the locking pin and the hole ha are roughly consistent, it is determined that the locking pin and the hole ha are engaged and hinder the rotation of the electric motor 4. Based on this state, the electric motor 4 is driven in the decompression direction by an amount corresponding to the angle of the gap equivalent to the hole ha, and the situation that the rotation of the electric motor 4 is hindered is determined again, thereby determining that the locking is completed. In this case, compared with the method of rotating the electric motor 4 in the decompression direction in the aforementioned step S20, the process becomes complicated and the operation time is prolonged, which is disadvantageous, but it is advantageous in that the braking load exceeding the parking brake load can be more reliably maintained.

[0129] When it is determined in step S15 that the third PKB operation state is in progress, the third PKB operation unit 24ac stops driving the electric motor 4 (step S24), and enters a locking operation completion state (step S25). As a method for stopping the driving of the electric motor 4, for example, a control state in which the operation amount (line voltage, phase current, etc.) equivalent to the torque is zero may be used, or at least one or both of the power supply and circuit drive signal to the electric motor driver 18 may be cut off, or all functions except the function required for restarting the control device 2 may be turned off.

[0130] When the operation amount is in a control state of zero, the motor can be driven quickly when a parking brake release request is issued. In addition, the operation amount of zero also includes a small operation amount that is almost regarded as zero.

[0131] When either or both of the power supply to the electric motor drive circuit and the drive circuit signal are cut off, the time lag until the electric motor 4 is driven again is prolonged, which is disadvantageous, but the power consumption during the drive stop of the electric motor 4 can be further reduced.

[0132] When all functions except the function required for restarting the control device 2 are turned off, the time lag until the electric motor 4 is driven again is the longest, which is disadvantageous, but the power consumption during the stop of the motor 4 can be minimized.

[0133] <Release action flow>

[0134] Figure 7 For about Figure 5 A flowchart of the release action recorded in S10.

[0135] After the process starts, the release control unit 24b determines whether the process execution state is the first execution (step S27). If it is the first execution, the current action state is initialized to the first PKB release action state (step S28). In addition, the first action means that the parking brake release action changes from the non-action state to the action state for the first time.

[0136] Next, the parking brake release state is determined (step S29). If the parking brake is in the first PKB release state, the first PKB release unit 24ba is used to rotate the electric motor 4 in the boost direction (step S30). The electric motor 4 may be rotated by brake load control, motor angle control, motor angular velocity control, etc., or by gradually increasing the electric motor current.

[0137] Next, the release control unit 24b determines whether the electric motor 4 has rotated by a predetermined amount (step S31). If the electric motor 4 has rotated by the predetermined amount (step S31: yes), the state is transferred to the second PKB release operation state (step S32). The predetermined amount can be set, for example, to the motor rotation amount that sufficiently separates the contact portion of the engaged portion Hk that restricts the rotation of the electric motor 4 in the engaged state of the parking brake mechanism 7. If the contact portion separates, the biasing mechanism of the solenoid 16 is used to separate the locking pin from the engaged portion Hk.

[0138] As the solenoid 16, an example of using a solenoid that can be driven by a solenoid coil and a force-applying mechanism is shown, but in the case of using a solenoid or a DC motor that can be driven in both directions, the locking pin can be disengaged from the engaged portion Hk by driving the locking pin in the direction in which the locking pin is disengaged from the engaged portion Hk while the electric motor 4 rotates in step S30. In addition, in the case where the protrusion time of the above-mentioned locking pin or the movable portion 15 equivalent to the locking pin cannot be ignored, a predetermined standby time for disengaging the movable portion 15 of the solenoid 16 can also be set.

[0139] When it is determined in step S29 that the second PKB release operation state is in progress, the electric motor 4 is rotated in the decompression direction by the second PKB release operation unit 24bb (step S33). The rotation of the motor 4 may be performed by brake load control, motor angle control, motor angular velocity control, etc., or the motor current may be gradually reduced and the motor 4 may be rotated by the brake reaction force. Next, it is determined whether the motor 4 has rotated by a predetermined amount (step S34). If the motor 4 has rotated by a predetermined amount (step S34: yes), the release operation is completed (step S35).

[0140] If the above-mentioned specified amount is, for example, the angle of the electric motor 4 locked before the parking brake release action is pre-stored, and is used to determine the specified amount when the electric motor 4 rotates at least to the decompression side compared to the above-mentioned angle, it is possible to accurately determine the situation where the movable part 15 is disengaged from the engaged part Hk, which is preferred.

[0141] also, Figure 5 to Figure 7 The "start" and "return" are recorded for convenience, and the processes from start to return in each figure do not necessarily need to be synchronized in the control cycle. In addition, the calculation order or judgment method, etc., can be appropriately changed according to the installation situation, etc. as long as there is no contradiction in the actions recorded in this embodiment.

[0142] Figure 8 2 is a diagram showing the state transition of the parking brake controller 24 .

[0143] As the initial state, if the parking brake is released, it is transferred to ST0, and if the parking brake is in the state, it is transferred to ST2. As to whether it is the above-mentioned parking brake state, for example, a non-volatile storage device (not shown in the figure) that stores whether the vehicle operation is completed in the parking brake state can be set in the control device 2, and the judgment is made based on the state stored in the non-volatile storage device, or a structure can be formed in which the initial state is indicated from the upper ECU of the vehicle. Alternatively, it can also be determined by communicating with Figure 6 Together with the above method, it is determined whether it is in the locked state, and whether it is in the parking brake state is determined based on the determination of whether it is in the locked state.

[0144] like Figure 8 As shown, when a parking brake request instruction is issued from the service brake state (ST0), the state is transferred to the parking brake locking action state (ST1). When the locking action is completed, the state is transferred from the parking brake locking action state (ST1) to the parking brake state (ST2). In addition, when a parking brake release request instruction is issued during the locking action and the locking action is interruptible, the state is transferred to the service brake state (ST0). Specifically, when the control device 2 receives an instruction to release the parking brake state through the parking brake switch Ps during the execution of the first PKB action unit 24aa, the braking force is followed by the target braking force given by the brake pedal Bp instead of the state in which the braking force is exerted independently of the brake pedal Bp. The above-mentioned situation in which the locking action can be interrupted can be set to a state in which the solenoid 16 is not driven, for example.

[0145] In the case of a locking action failure, if a retry is possible, the parking brake locking action state (ST1) is transferred again to the parking brake locking action state (ST2). Specifically, the control device 2, in the execution of the second PKB action unit 24ab, at least according to the motion state estimator 22, when the electric motor 4 exceeds the engagement spacing Pc ( Figure 3 ) is rotated, it is determined that the engagement of the parking brake mechanism 7 has failed, and the first and second parking brake actions are performed again one or more times.

[0146] If retry is not possible, the vehicle is transferred to the service brake state (ST0). The failure of the above locking action can be determined, for example, by performing the second PKB action ( Figure 6 ), the motor 4 rotates a predetermined amount in the decompression direction in the unlocked state to judge, and the predetermined amount can be determined, for example, based on the engagement spacing of the engaged portion Hk. In addition, regarding the retry / non-retry, for example, a function of storing the number of retries can be set in the control device 2, and when the number of retries exceeds a predetermined value, it is set to non-retry. It is also possible to set a function to convey the abnormal parking brake action to the vehicle operator through a mechanism such as a lamp when it is judged that the above-mentioned non-retry is not possible.

[0147] When a parking brake release request is issued from the parking brake state (ST2), the state is transferred to the parking brake release action state (ST3). When the release action is completed, the state is transferred from the parking brake release action state (ST3) to the service brake state (ST0). When a parking brake request is issued in the parking brake release action state (ST3), the state is transferred to the parking brake lock action state (ST1).

[0148] In addition, in the parking brake release action state (ST3), if the release action fails, if a retry is possible, the parking brake release action state (ST3) is transferred again. Specifically, when the control device 2 determines that the rotation of the electric motor 4 is hindered by the parking brake mechanism 7 at least according to the motion state estimator 22 during the execution of the second PKB release action unit 24bb, it is determined that the parking brake release has failed, and the first PKB release action unit 24ba is executed once or more.

[0149] If the retry fails, the vehicle is transferred to the parking brake state (ST2). The failure of the above release action can be determined, for example, by the following method: Figure 7 ) is locked during the process. In addition, regarding the above-mentioned retry / non-retry, for example, a function of storing the number of retries may be provided in the control device 2, and when the number of retries exceeds a specified value, the retry is set to be non-retryable. A function may also be provided to notify the vehicle operator of the abnormal parking brake operation through a mechanism such as a lamp when it is determined that the above-mentioned retry is non-retryable.

[0150] <Operation Example of Parking Brake Mechanism 7>

[0151] Fig. 9 This is a diagram showing an operation example of the electric brake device.

[0152] At time t1, if the first PKB action starts, the braking load rises to the specified value. If the specified braking load is reached at time t2, the state is transferred to the second PKB action state. Then, while the solenoid 16 is driven, the electric motor 4 is rotated in the decompression direction. When the positional relationship between the engaged portion Hk and the movable portion 15 of the solenoid 16 reaches the specified engagement position, the engaged portion Hk is locked by the solenoid 16 and is in a state where the rotation of the electric motor 4 is hindered (time t3). Then, the drive of the electric motor 4 is stopped, and the locking action is completed (time t3→t4).

[0153] The release operation starts at time t4, and after the electric motor 4 is rotated by a predetermined amount in the direction of increasing the braking load pressure, the electric motor angle is maintained substantially constant until the movable part 15 of the solenoid 16 is reliably disengaged. Then, the electric motor 4 is rotated in the direction of reducing pressure from time 5, and at time t6, the electric motor 4 rotates by a predetermined amount, thereby confirming that the lock is released, and the release operation is completed.

[0154] <Effects>

[0155] According to the electric brake device 1 described above, the control device 2 follows and controls the braking force with respect to the target braking force applied from the brake pedal Bp during the release of the parking brake.

[0156] When the parking brake switch Ps sends an instruction to the control device 2 to be in the parking brake state, the first parking brake operating unit 24aa, the second parking brake operating unit 24ab, and the third parking brake operating unit 24ac are sequentially executed.

[0157] First, when the first PKB actuator 24aa receives an indication of the parking brake state during the parking brake release process, it exerts a braking force regardless of the brake pedal Bp. The first PKB actuator 24aa further determines that a braking force exceeding the braking force that should be exerted in the parking brake state is exerted.

[0158] After this determination, the second PKB operation unit 24ab engages the movable portion 15 with the engaged portion Hk, and rotates the electric motor 4 in a direction to reduce the braking force. Thus, the engaged portion Hk and the movable portion 15 are engaged in a so-called locked state.

[0159] Thereafter, the third PKB actuator 24ac is in a parking brake state in which the electric motor 4 is not caused to generate drive power.

[0160] When the vehicle is shifted to the parking brake state as described above, the vehicle sequentially performs the actions of exerting a braking force equivalent to the parking brake, locking the parking brake mechanism 7, and suppressing the power consumption of the electric motor 4 while maintaining the parking brake state. This reduces erroneous operations and enables correct parking brake operation.

[0161] In addition, the release control unit 24b of the parking brake controller 24 reduces erroneous operations and enables accurate parking brake release operations by sequentially rotating the electric motor 4 toward the boosting side to disengage the movable part 15 from the engaged part Hk and decompressing the vehicle to release the parking brake load from the parking brake state.

[0162] <About other implementations>

[0163] Next, other embodiments are described. In the following description, the same reference numerals are used for the parts corresponding to the matters previously described in each embodiment, and repeated descriptions are omitted. In the case of describing only a part of the structure, the other parts of the structure are the same as those previously described unless otherwise specified. The same structure has the same effect. Not only the combination of the parts specifically described in each embodiment, but also the embodiments can be partially combined with each other as long as there is no particular obstacle to the combination.

[0164] Fig.10For example, the upper ECU 17 such as the vehicle control unit (VCU) that controls the entire vehicle includes a brake command mechanism 17a and a parking brake command mechanism 17b. The brake command mechanism 17a in the upper ECU 17 sends a brake command signal as a target braking force to the control device 2, and the parking brake command mechanism 17b sends an indication of whether the vehicle is in a parking brake state to the control device 2. The function of the upper ECU 17 may be a function of generating a brake command signal according to the operation state of the brake pedal, etc., or a function of generating a command signal that is not dependent on the operator of automatic braking, automatic driving, etc.

[0165] Can also be used in conjunction Figure 4 , Fig.10 For example, the brake command mechanism 17a may be based on the operation of the brake pedal Bp, and the parking brake command mechanism 17b may be a command signal from the upper ECU 17. Alternatively, the brake command mechanism 17a may be a command signal from the upper ECU 17, and the parking brake command mechanism 17b may be a parking brake switch Ps or the like.

[0166] like Figure 4 , Fig.10 As shown by the imaginary line of , the output of the current sensor 20 can also be obtained in the parking brake controller 24. As described above, the current sensor value can be used to determine whether the electric motor 4 is locked during the parking brake operation.

[0167] also, Figure 4 , Fig.10 The functional blocks shown are only provided for the convenience of description and do not limit the structure or partition of hardware or software. The specific structure of software and hardware may be Figure 4 , Fig.10 The functions of the blocks shown in the figure can be arbitrarily configured within the scope of the functions shown in the figure. In addition, the functions of the blocks shown in the figure can be merged or divided as needed. Alternatively, elements other than those shown in the figure can be added within the scope that does not hinder the functions of the figure. For example, additional controls such as anti-skid control of the electric brake device, pad clearance control when the brake is released, and lateral slide prevention control, as well as other safety mechanisms, can be appropriately added according to the necessary conditions of the system.

[0168] <Other structural examples of the engaged portion Hk>

[0169] Fig.11 (a) is a front view of another first gear-shaped portion 13a, Fig.11 (b) is along Fig.11 The cross-sectional view along the line XI(b)-XI(b) in (a) is shown in FIG. Fig.11 (c) is along Fig.11 The cross-sectional view of line XI(c)-XI(c) in (a). Fig.11 In the embodiment, a through hole ha in the shape of a circumferentially long hole is provided in the engaged portion Hk. The through hole ha has an inclined surface 34 which can lock the engaging portion only in one rotational direction and can unlock the engaging portion in the other rotational direction which is the opposite direction.

[0170] The inclined surface 34 is set to a predetermined angle relative to the driving direction of the engaging portion, which is an inclined angle at which the through hole ha narrows in the circumferential direction as the through hole ha protrudes toward the engaging portion. In addition, the inclined surface 34 is formed to be curved to match the outer peripheral surface shape of the engaging portion. When the lock is released, the first gear-shaped portion 13a is rotated in the other direction of the rotation direction by the drive of the electric motor, and the top end portion of the engaging portion retreats along the inclined surface 34, thereby enabling the lock to be released. In addition, the outermost diameter of the second gear-shaped portion 13b is arranged at a position closer to the inner side in the radial direction than the through hole ha.

[0171] In the example of this figure, the hole shape is relatively complex. However, in the case where the reverse input is only required in one direction, such as in the parking brake mechanism of an electric brake device, the engagement of the engagement portion can be released by rotating the electric motor in the direction opposite to the reverse input. Therefore, reliability comparison can be performed. Figure 2 Examples of structures for higher actions.

[0172] Fig.12 (a) is a front view of another first gear shape portion 13a, Fig.12 (b) is along Fig.12 The cross-sectional view along the line XII(b)-XII(b) in (a) is shown in FIG. Fig.12 (c) is along Fig.12 A cross-sectional view taken along line XII(c)-XII(c) in (a). Fig.12 The example of evenly setting a plurality of radially extending grooves mz for engaging and disengaging the movable part on the circumference of the engaged part Hk is shown. The example of this figure has the advantages of simple shape and reduced processing cost. In addition, it is preferred that, even if the difference between the outer diameter of the second gear-shaped part 13b and the outer diameter of the first gear-shaped part 13a is relatively small, since each groove mz does not penetrate the first gear-shaped part 13a, the first and second gear-shaped parts 13a and 13b can be integrally formed as a single member.

[0173] Fig.13 (a) is a front view of another first gear shape portion 13a, Fig.13 (b) is along Fig.13 The cross-sectional view of line XIII(b)-XIII(b) in (a). Fig.13 In the embodiment, a plurality of through holes ha (10 in this example) are evenly arranged on the circumference of the engaged portion Hk, and each through hole ha is composed of a simple circular hole shape. In addition, the outermost diameter of the second gear-shaped portion 13b is arranged at a position radially inward of the through holes ha.

[0174] The example of this figure has the advantage that the hole shape is simple and the processing cost can be reduced. In addition, a plurality of holes can be provided at a relatively short pitch Pc, thereby improving the accuracy of the holding load of the reverse input holding.

[0175] Fig.14 (a) is a front view of another first gear shape portion 13a, Fig.14 (b) is along Fig.14 The cross-sectional view along the line XIV(b)-XIV(b) in (a) is shown in FIG. Fig.14 (c) is along Fig.14 The cross-sectional view along the line XIV(c)-XIV(c) in (a). Fig.14 In, with Fig.11 Similarly, the engaged portion Hk is provided with a circumferentially long hole-shaped groove mz having an inclined surface 34 that can lock the engaging portion only in one rotational direction and can be unlocked in the other rotational direction which is the opposite direction.

[0176] In this Fig.14 In the example of FIG. 1 , the hole shape is relatively complex. However, for example, in the case where the reverse input is maintained in only one direction, such as in the parking brake mechanism of the electric brake device, the engagement of the engagement portion can be released by rotating the electric motor in the direction opposite to the reverse input. Figure 2 In addition, since each groove mz does not penetrate the first gear-shaped portion 13a, it is preferable that the first gear-shaped portion 13a and the second gear-shaped portion 13b are integrally formed as a single member.

[0177] Fig.15 (a) is a front view of another first gear shape portion 13a, Fig.15 (b) is along Fig.15 The cross-sectional view of line XV(b)-XV(b) in (a) is shown in FIG. Fig.15 (c) is along Fig.15 The cross-sectional view of the line XV(c)-XV(c) in (a). Fig.15In the figure, there is shown an example in which a plurality of protrusions Tk are evenly arranged on the end face of the first gear-shaped portion 13a. The movable portion is configured so as to be engageable and disengageable with the groove 35 between the protrusions Tk and Tk adjacent to each other in the circumferential direction. The protrusions Tk of this example are integrally arranged on the first gear-shaped portion 13a, but may also be configured as a structure fixed as an independent component relative to the first gear-shaped portion 13a. In the example of this figure, the protrusions Tk are only arranged on the end face, so it is preferred that the processing cost is excellent and the degree of freedom of the shape of the protrusions Tk is relatively high.

[0178] In each embodiment, an example of providing a hole ha for engagement on the end face of a gear is shown, but as long as the hole ha for engagement is provided on a component other than a gear, the hole ha for engagement may be provided. For example, a hole for engagement may be provided on the end face of a rotating shaft of an electric motor, and a solenoid may be arranged opposite to it.

[0179] As the electric motor 4, for example, a DC motor using a brush, a reluctance motor not using a permanent magnet, or an induction motor may be used.

[0180] The reducer 5 may be, for example, a planetary gear, a worm gear, a harmonic reducer, etc. The linear motion mechanism 6 may be various screw mechanisms such as planetary roller screws and ball screws, and various mechanisms such as ball ramps that convert rotational motion into linear motion by tilting the rotation axis circumferentially.

[0181] As described above, the preferred embodiments have been described with reference to the drawings, but various additions, changes, and deletions may be made without departing from the gist of the present invention. Therefore, such technical solutions are also included in the scope of the present invention.

[0182] Description of the label:

[0183] Reference numeral 2 denotes a control device; reference numeral 4 denotes a motor; reference numeral 6 denotes a linear motion mechanism (friction member operating mechanism); reference numeral 7 denotes a parking brake mechanism; reference numeral 8 denotes a brake rotor; reference numeral 9 denotes a friction member; reference numeral 15 denotes a movable portion; reference numeral 18 denotes a motor driver (drive circuit); reference numeral 22 denotes a motion state estimator (motor motion estimating mechanism); reference numeral 23 denotes a control operator; reference numeral 24aa denotes a first parking brake actuating portion; reference numeral 24ab denotes a second parking brake actuating portion; reference numeral 24ac denotes a third parking brake actuating portion; reference numeral 24ba denotes a first parking brake releasing actuating portion; reference numeral 24bb denotes a second parking brake releasing actuating portion; symbol Bp denotes a brake pedal (brake command mechanism); symbol Hk denotes an engaged portion; and symbol Ps denotes a parking brake switch (parking brake command mechanism).

Claims

1. An electric brake device, comprising: A brake rotor; a friction member that abuts against the brake rotor to generate a braking force; an electric motor; a friction member operating mechanism that operates the friction member through the electric motor; a control device having a control operator that calculates an operation amount of the electric motor, the electric motor operation amount being used to make the braking force follow: a target braking force provided by a drive circuit that drives the electric motor and a brake command mechanism; The electric brake device comprises: A parking brake mechanism, the parking brake mechanism comprising an engaged portion and a movable portion, the engaged portion moving synchronously with the rotation of the electric motor, the movable portion being movable in engagement and disengagement relative to the engaged portion, wherein the movable portion is engaged with the engaged portion to hinder movement synchronous with the rotation of the electric motor, and the braking force generated by the contact between the brake rotor and the friction member is maintained independently of the driving force of the electric motor; a parking brake command mechanism, the parking brake command mechanism sending an instruction to the control device as to whether to adopt the parking brake mechanism to form the following parking brake state, in which the braking force does not follow the command value of the brake command mechanism and maintains the determined braking force; The control device includes: a braking force estimation mechanism for estimating the braking force; a motor motion estimation mechanism for estimating the motion state of the electric motor, the motion state of the electric motor including at least the angle of the electric motor or the calculus value of the angle, or any one of the motion quantities equivalent to the angle or the calculus value of the angle; The above control device comprises: a first parking brake actuating unit which, when receiving an instruction to be in the parking brake state from the parking brake command unit during the parking brake release that is not in the parking brake state, exerts the braking force independently of the brake command unit and determines, at least based on the braking force estimating unit, that a braking force exceeding a braking force that should be exerted in the parking brake state is exerted; a second parking brake actuating unit, which, after the judgment of the first parking brake actuating unit, is in a state of engaging the movable portion with the engaged portion, and rotates the electric motor in a direction of reducing the braking force at least according to the motor motion estimation mechanism, thereby engaging the engaged portion with the movable portion to hinder the rotation of the electric motor; a third parking brake actuating unit, wherein after the execution of the second parking brake actuating unit, the third parking brake actuating unit is in a parking brake state in which the electric motor does not generate driving power; a first parking brake releasing action unit, which, in the parking brake state, when receiving an instruction to release the parking brake state through the parking brake command mechanism, is in a state in which the movable part is disengaged from the engaged part, and, based on at least one or both of the braking force estimating mechanism and the motor motion estimating mechanism, rotates the electric motor in the direction of increasing the braking force from the state in which the parking brake release is started, so that the rotation state of the electric motor is in a state in which the movable part can be disengaged; A second parking brake releasing action unit, after the execution of the first parking brake releasing action unit, rotates the electric motor in a manner that reduces the braking force at least as compared to the parking brake state based on at least one or both of the braking force estimating mechanism and the motor motion estimating mechanism, and determines that the parking brake release is completed based on the rotation amount of the electric motor exceeding a specified amount.

2. The electric brake device according to claim 1, wherein: During the execution of the first parking brake actuation unit, when the control device receives an instruction to release the parking brake state through the parking brake command mechanism, the control device performs follow-up control on the braking force relative to the target braking force provided by the brake command mechanism, without relying on the brake command mechanism to exert the braking force.

3. The electric brake device according to claim 1 or 2, wherein: The control device has a function of estimating the external disturbance torque acting on the electric motor based on at least the motor motion estimation mechanism; During the execution of the second parking brake actuation unit, the control device determines that the rotation of the electric motor is hindered due to the engagement of the parking brake mechanism when the calculated external disturbance torque is greater than the torque determined in the direction corresponding to the brake boost direction.

4. The electric brake device according to claim 1 or 2, wherein: The control device has the function of estimating the current of the electric motor; During the execution of the two parking brake actuating units, the control device determines that the rotation of the electric motor is hindered due to the engagement of the parking brake mechanism when a current greater than a certain current that generates torque in a direction corresponding to the brake decompression direction is calculated.

5. The electric brake device according to claim 1, wherein: The engaged portion and the movable portion have an engagement interval, and the engagement interval is a positional relationship that allows engagement whenever the electric motor rotates a predetermined angle; During the execution of the second parking brake action unit, the control device determines that the engagement of the parking brake mechanism has failed when the electric motor rotates beyond the engagement interval, at least based on the motor motion estimation mechanism, and executes the first parking brake action and the second parking brake action one or more times.

6. The electric brake device according to claim 1, wherein: During the execution of the second parking brake releasing action unit, the control device determines that the rotation of the electric motor is hindered by the parking brake mechanism at least based on the motor motion estimation mechanism, and when the rotation of the electric motor is hindered, it determines that the parking brake release has failed, and executes the first parking brake releasing action unit more than once.

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