JP2006213323A - Electric parking brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the usability of an electric parking brake device provided with a plurality of parking brakes provided on a plurality of wheels and driven by an electric motor respectively. <P>SOLUTION: PKB switching switch 300 switchable to a first operation position for achieving a state in which all brakes 16 are operated as parking brakes and a second operation position achieving a state in which only the brakes 16 of the rear two wheels RL, RR are operated as the parking brakes is provided on the vehicle in which all brakes 16 of the four wheels FL, FR, RL, RR can be operated as the parking brakes. It is facilitated for a driver to spin-turn the vehicle by switching the PKB switching switch 300 to the second operation position, which enhances the usability of the electric parking brake device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electric parking brake device provided in a vehicle, and more particularly, to a technique for improving its usability.

  In general, parking of a vehicle is mechanically performed by a driver operating a parking brake operation member such as a parking lever or a parking pedal. On the other hand, Japanese Patent Laid-Open No. 4-108058 discloses an electric parking brake device that electrically parks a vehicle. According to this device, the operation force required for parking the vehicle is reduced.

Problems to be solved by the invention, problem solving means, actions and effects

  In the electric parking brake device described above, since all the brakes of the left and right front wheels and the left and right rear wheels of the vehicle are operated as parking brakes, the operating force of the entire vehicle can be increased relative to the operating force of each parking brake. There is an advantage. However, this electric parking brake device cannot achieve the same usability as a conventional mechanical parking brake device. For example, in a conventional mechanical parking brake device, parking brakes are generally provided only on the left and right rear wheels, and the driver can actively use this to spin the vehicle. However, the electric parking brake device described in the above publication cannot enjoy the advantages of such a conventional mechanical parking brake device.

In view of such circumstances, the present invention has been made to provide an electric parking brake device that is easy to use.
This problem is solved by the following aspects. In the following description, each aspect is described in the same format as the claims, with each item numbered. This is to clearly show the possibility of adopting a combination of the features described in each section.
The parking brake device according to the following items (1) to (22) and (33), and the brake related quantity detecting device according to the items (29) to (32) are described in the present claims. It is not an embodiment of the invention.

(1) A vehicle comprising a power source, a plurality of wheels driven by at least one of the power source, and a power source switch operated by a driver at an operating position where the power source is operated and a non-operating position where the power source is not operated (I) a parking brake provided on at least one of the plurality of wheels; (ii) an electric motor that operates the parking brake; and (iii) a state in which no electric power is supplied to the electric motor. And (iv) supplying electric power to the electric motor to operate the parking brake and cutting off the electric power supply to the electric motor in the operating state. Thus, in an electric parking brake device including a parking brake control device for parking the vehicle,
In the state where the power source switch is in the non-operating position, the parking brake control device is supplied with electric power to the electric motor, thereby changing the actual operating force of the parking brake, and then supplied with electric power to the electric motor. An electric parking brake device characterized in that an actual operating force changing device is provided.
In a mechanical parking brake device that mechanically parks a vehicle, a power source switch (ignition switch, main switch) that is operated between an operating position for operating a power source (engine, motor, etc.) of the vehicle and a non-operating position for not operating the vehicle. Even when the power switch or the like is in the non-operating position, the actual operating force of the parking brake can be increased or decreased, or the parking brake can be released. On the other hand, the publication discloses that the electric parking brake device can increase or decrease the actual operating force of the parking brake or release the parking brake with the power source switch in the non-operating position. Does not teach you to design to be. Therefore, in this electric parking brake device, when the power source switch is in the non-operating position, the actual operating force of the parking brake cannot be increased or decreased, and the parking brake cannot be released. Although the parking brake device has an advantage that the operation force is reduced as compared with the conventional mechanical parking brake device, there is a drawback that the usability is inferior.
On the other hand, according to the electric parking brake device of this section, it is possible to change the actual operating force of the parking brake even when the power source switch is in the non-operating position, thereby improving the usability of the electric parking brake device. improves.
In addition, according to this device, when it is not necessary to change the actual operating force of the parking brake, the parking brake is actually used without supplying power to the electric motor by using the operating force holding mechanism. Since the operating force is maintained, it is possible to suppress an increase in the amount of power consumed by the electric motor due to the fact that the actual operating force of the parking brake can be changed at the non-operating position of the power source switch.
In this apparatus, the “power source” includes an engine, an electric motor, and the like.
The “power source switch” includes an ignition switch, a key switch, a main power switch, and the like.
The “change in actual operating force” includes increasing / decreasing the actual operating force, and “decreasing” includes releasing the parking brake.
Further, the “parking brake control device” can be configured to perform or not perform parking brake control when the power source switch is in the operating position.
(2) The electric parking brake device according to (1), further including a parking brake operation member, wherein the parking brake control device starts operating in response to the operation of the parking brake operation member.
(3) The electric parking brake device according to (1), wherein the parking brake control device starts operating in response to the power source switch being operated from the operating position to the non-operating position.
(4) After the parking brake control device is in a state where the power source switch is in the non-operating position and the power supply to the electric motor is cut off after the actual operating force of the parking brake is changed, the parking brake The electric parking brake device according to any one of (1) to (3), further including power supply blocking means for blocking power supply to the electric motor until a new necessity to change the actual operating force of the motor is generated.
According to this device, the actual operating force of the parking brake can be changed while suppressing an increase in power consumption by the electric motor while the power source switch is in the non-operating position.
(5) The actual operating force change device includes: (a) a parking brake operation member; and (b) power supply means for supplying power to the electric motor based on an operation of the parking brake operation member. The electric parking brake device according to any one of items (4) to (4).
(6) The actual operating force changing device includes: (a) a parking brake release switch operated by a human to release the parking brake and make its actual operating force zero; and (b) the power source switch. (1) to (5) including first motor control means for controlling the electric motor so that the parking brake is released when the parking brake release switch is operated in a state where the parking brake is released. The electric parking brake device according to any one of the above items.
According to this device, the parking brake can be released even when the power source switch is in the non-operating position, thereby improving the usability of the electric parking brake device.
Here, the “human” includes not only the driver but also an operator who repairs the vehicle.
The “parking brake release switch” is an example of the “parking brake operation member” in the above item (5).
(7) The first motor control means starts operation when the parking brake release switch is operated at the same time as the power source switch is operated from the operating position to the non-operating position (6) The electric parking brake device according to item.
According to this apparatus, since the parking brake is released in response to two operating members being operated almost simultaneously, compared to the case in which the parking brake is released in response to one operating member being operated. Thus, the release of the parking brake due to an erroneous operation can be avoided more reliably.
(8) The actual operating force changing device is (a) a manual target operating force setting device that sets a target operating force of the parking brake in response to a human command, and (b) the power source switch is in a non-operating position. And a second motor control means for controlling the electric motor so that an actual operating force of the parking brake becomes equal to a set target operating force. The electric parking brake device described in 1.
According to this device, the actual operating force of the parking brake can be changed even when the power source switch is in the non-operating position, thereby improving the usability of the electric parking brake device.
Here, the “human command” can be transmitted by a human operation or transmitted by voice, for example.
Further, the “manual target operating force setting device” has a mode in which the target operating force is set as a continuous value that continuously changes according to a human command, or a mode in which the target operating force is set as a step value that changes stepwise. be able to.
Further, in the case where the “manual target operating force setting device” has an operation member that is operated by a human to adopt a form in which a human command is transmitted by a human operation, the operation member is the above (5 ) Is an example of the “parking brake operation member”.
(9) In the period from the time when the power source switch is operated from the non-operating position to the operating position until the time when the parking brake operation is first released thereafter, the actual operating force changing device The electric parking brake device according to item (8), including actual operating force holding means for holding the actual operating force of the parking brake regardless of a change in the setting of the operating force.
In this device, the manual target operating force setting device in which the target operating force is changed continuously or stepwise according to a human command, the human operating the power source switch from the non-operating position to the operating position. Before the first command to release the parking brake operation from the time when the parking brake is operated, the switch functions as a switch that can be switched between two positions, a position where the parking brake is released and a position where the parking brake is not released. On the other hand, in the conventional mechanical parking brake device, when the parking brake is released, the parking brake operating member suddenly changes from a non-zero magnitude to 0 when the parking brake is released. Functions as a switch. Therefore, according to the electric parking brake device described in this section, an operation feeling equivalent to that of the conventional mechanical parking brake device can be obtained when the parking brake is released.
(10) The actual braking force changing device can change the actual operating force of the parking brake at any time in a state where the power source switch is in the non-operating position. Electric parking brake device.
Here, “change in actual operating force” includes increasing / decreasing the actual operating force, and “decreasing” includes releasing the parking brake.
(11) The power supply blocking means for blocking the power supply to the electric motor after the set time has elapsed from the time when the power source switch is operated from the operating position to the non-operating position. The electric parking brake device according to any one of (1) to (9).
In the electric parking brake device described in the above item (10), the actual operating force of the parking brake can be changed at any time while the power source switch is in the non-operating position. However, when this apparatus is used, there is a problem that the amount of power consumption tends to increase. This is because as long as the power source switch is in the non-operating position, it must be determined whether or not it is necessary to change the actual operating force of the parking brake. On the other hand, according to the electric parking brake device described in this section, the actual operating force of the parking brake is changed only during the set time from the time when the power source switch is operated from the operating position to the non-operating position. It is possible. Therefore, according to this device, it is possible to improve the usability of the electric parking brake while suppressing an increase in power consumption by the electric motor.
Here, the “power supply blocking means” can be, for example, a mode in which blocking of power supply to the electric motor is continued until the power source switch is operated from the non-operating position to the operating position.
(12) The actual braking force changing device includes: (a) a parking brake operation member; and (b) the electric motor based on an operation of the parking brake operation member in a state where the power source switch is in an inoperative position. An actual operating force changing means for supplying electric power, thereby changing the actual operating force of the parking brake, and then cutting off the electric power supply to the electric motor; and (c) the power source switch from the operating position to the non-operating position. After the set time has elapsed from the time of operation, the power supply to the electric motor is blocked regardless of the operation of the parking brake operation member until the power source switch is operated from the non-operating position to the operating position. The electric parking brake device according to any one of (1) to (11), further including:
According to this device, it is possible to improve the usability of the electric parking brake while suppressing an increase in power consumption by the electric motor.
(13) Further, the system further includes an operating force sensor that detects an actual operating force of the parking brake, and the actual operating force changing device is configured so that the actual operating force detected by the operating force sensor is equal to the target operating force. The electric parking brake device according to any one of (1) to (12), further including third motor control means for controlling the electric motor.
(14) The actual operating force changing device includes: (a) an automatic target operating force setting device that sets a target operating force of the parking brake according to the state of the vehicle or the road surface; and (b) the power source. And (4) motor control means for controlling the electric motor so that an actual operating force of the parking brake becomes equal to a set target operating force in a state where the switch is in the non-operating position. The electric parking brake device according to any one of items 1).
According to this device, it is possible to prevent the actual operating force of the parking brake from being insufficient or excessive.
The feature described in this section can be adopted independently of the feature described in the above section (1).
(15) The automatic target operating force setting device includes: (a) a vehicle speed sensor that detects the speed of the vehicle; and (b) when the vehicle is not stopped based on a detection value of the vehicle speed sensor. Includes a target operating force increasing means for increasing the target operating force. (14) The electric parking brake device according to item (14).
(16) The automatic target operating force setting device is based on (a) a road surface inclination angle sensor that detects an inclination angle of a road surface on which the vehicle is traveling, and (b) a detection value of the road surface inclination angle sensor, The electric parking brake device according to (14) or (15), further comprising target operating force setting means for setting the target operating force so that the vehicle does not start due to the inclination of the road surface.
(17) The electric parking brake device according to any one of (1) to (16), wherein the electric parking brake device is provided exclusively for a parking brake.
(18) The parking brake and the electric motor are used to electrically perform the main brake when the main brake is operated, so that the parking brake and the electric brake are shared by the main brake and the parking brake. The electric parking brake device according to any one of the above.
Here, the “main brake operation” refers to a brake operation performed to decelerate or stop the vehicle while the vehicle is running, and is also referred to as a normal brake operation.
(19) The electric motor is an ultrasonic motor that generates a stationary holding torque when power is not supplied to the electric motor, and the operating force holding mechanism generates a portion of the ultrasonic motor that generates the stationary holding torque. The electric parking brake device according to any one of (1) to (18).
(20) The operating force holding mechanism is provided between the electric motor and the parking brake, and allows transmission of force from the electric motor to the parking brake, but prevents transmission of force in the opposite direction. The electric parking brake device according to any one of (1) to (18), including a direction transmission mechanism.
(21) The one-way transmission mechanism includes a worm gear that rotates by meshing a worm and a worm wheel, the worm gear having the electric motor on the worm side and the parking brake on the worm wheel side. The electric parking brake device according to the item).
(22) A combination of the parking brake, the electric motor, and the operating force holding mechanism provided on each of the plurality of wheels, and the parking brake control device operating at the same time among the plurality of parking brakes. The electric parking brake device according to any one of (1) to (21), including a combination changing device to be changed.
According to this device, it is possible to change the combination of a plurality of parking brakes that are operated at the same time, and the usability of the electric parking brake device is improved.
(23) provided in a vehicle having a plurality of wheels, (i) a plurality of parking brakes provided on each of the plurality of wheels, and (ii) a plurality of electric motors that respectively operate the plurality of parking brakes, (iii) In an electric parking brake device including a parking brake control device for parking the vehicle by supplying electric power to each of the plurality of electric motors and operating the parking brake corresponding to each electric motor,
An electric parking brake device, wherein the parking brake control device is provided with a combination changing device for changing a combination of the plurality of parking brakes that are operated at the same time.
According to this device, as in the device described in the above item (22), the combination of the plurality of parking brakes that are operated at the same time can be changed, and the usability of the electric parking brake device is improved.
Each feature described in this section and the following section can be adopted together with each feature described in the above sections (1) to (21).
(24) The combination changing device includes: (a) a combination changing operation member operated by a human to change the combination; and (b) a manual operation for changing the combination based on an operation of the combination changing operation member. The electric parking brake device according to the item (22) or (23), including correspondence changing means.
According to this device, the combination of the parking brakes to be operated can be changed according to a human operation.
(25) The combination changing device includes: (c) a vehicle motion state amount sensor that detects a vehicle motion state amount representing a motion state of the vehicle such as a steering angle, a steering angle change speed, and a vehicle speed of the vehicle; The electric parking brake device according to any one of (22) to (24), further comprising automatic changing means for changing the combination based on a detection value of the vehicle motion state quantity sensor.
According to this device, the combination of the parking brakes to be operated can be automatically changed based on the vehicle motion state quantity.
(26) The plurality of wheels are respectively provided on the front, rear, left and right of the vehicle, and the combination includes a first combination including all wheels and a second combination including left and right rear wheels ( The electric parking brake device according to any one of items 22) to (25).
According to this device, it becomes easy to spin-turn the vehicle by selecting the second combination.
(27) The combination changing device selects the second combination when the driver may wish to spin-turn the vehicle, and selects the first combination otherwise. The electric parking brake device according to item (26), including combination selection means for performing the operation.
According to this device, an appropriate combination is automatically selected to cause the vehicle to spin-turn when the driver may wish to spin-turn the vehicle.
(28) The combination selection means is at least one of an absolute value of the steering angle of the vehicle exceeding a reference value, an absolute value of the steering angular velocity exceeding a reference value, and a vehicle speed being lower than the reference value. (27) The electric parking brake device according to (27), which includes a determination unit that determines that the driver may desire to spin-turn the vehicle when one of the conditions is established.
(29) A device for detecting a brake-related quantity related to the operation of the brake device,
Three sensors each for detecting the brake-related quantity;
When two or more of the three detection values detected simultaneously by the three sensors respectively match each other, either one of the two or more detection values that match each other or their total value is set. An actual value determining device for determining an actual value of the brake-related amount.
For three sensors that detect the same physical quantity or detect the same but not related physical quantity, two or more sensors will not fail at the same time, and always two or more sensors are normal It is possible to assume. Under this assumption, the fact that any two or more sensors corresponding to two or more detection values that match each other among the three detection values of the three sensors is normal can be derived. Based on such knowledge, in the apparatus described in this section, when two or more of the three detection values of the three sensors match each other, two or more detection values that match each other. Any of these two or more detected values or their total value is determined as the actual value of the brake-related amount. Therefore, according to this device, unless two or more of the three sensors fail at the same time, the brake-related amount can be detected with high accuracy, and the fault tolerance of the device is improved.
Here, the “brake-related amount” can be, for example, a brake operation force, a brake operation stroke, a booster negative pressure, a master cylinder hydraulic pressure, a brake cylinder hydraulic pressure, a vehicle body deceleration, a vehicle yaw rate, a vehicle lateral acceleration, and the like.
As the “sensor”, any sensor mounted on a vehicle can be used. For example, a stroke sensor such as a brake operation stroke sensor or a force sensor such as a brake operation force sensor can be used. , Master cylinder fluid pressure sensor, booster negative pressure sensor, brake cylinder fluid pressure sensor, etc. Adopt pressure sensor, vehicle speed sensor, yaw rate sensor etc., speed sensor, car body deceleration sensor, car body acceleration sensor, etc. It is possible to employ an acceleration / deceleration sensor.
Each feature described in this section and the following section can be adopted together with each feature described in the above (1) to (28).
(30) The brake related amount detection device according to (29), wherein the total value is an average value of the two or more detection values that match each other.
(31) The brake-related quantity detection device according to (29) or (30), wherein the three sensors detect the same physical quantity as the three brake-related quantities.
In this apparatus, the three sensors can be configured as, for example, three brake operation stroke sensors, or can be configured as three master cylinder hydraulic pressure sensors.
(32) The three sensors detect the three brake-related quantities, of which two or more of them are not the same as a physical quantity but are related to each other. (29) or (30) Brake-related quantity detection device.
In this apparatus, the three sensors are configured, for example, as a brake operation stroke sensor, a brake operation force sensor, and a master cylinder hydraulic pressure sensor, or as a brake operation stroke sensor, a master cylinder hydraulic pressure sensor, and a vehicle body deceleration sensor. be able to.
(33) A vehicle including a power source, a plurality of wheels driven by at least one of the power source, and a power source switch operated by a driver at an operating position where the power source is operated and a non-operating position where the power source is not operated Provided in
A parking brake provided on at least one of the plurality of wheels;
An electric motor for operating the parking brake;
An electric parking brake device including a parking brake control device for parking the vehicle by supplying electric power to the electric motor and operating the parking brake;
The parking brake control device is provided with an actual operating force change device that supplies electric power to the electric motor in a state where the power source switch is in the non-operating position, thereby changing the actual operating force of the parking brake. An electric parking brake device.
According to this device, the actual operating force of the parking brake can be changed even when the power source switch is in the non-operating position, thereby improving the usability of the electric parking brake device.

Hereinafter, some of more specific embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 shows a brake system including an electric parking brake device according to a first embodiment of the present invention. The first embodiment and the second embodiment to be described later are not embodiments of the invention described in the present claims, but are described for use in explaining the embodiments of the invention described in the claims. To do.
This brake system is provided in a four-wheeled vehicle including left and right front wheels FL and FR and left and right rear wheels RL and RR. This vehicle includes an engine (internal combustion engine) 10 as a power source and an automatic transmission (hereinafter abbreviated as “AT”) 12 as a driving force transmission device. Drive wheels, which are at least one of the front wheels and the left and right rear wheels, are driven, thereby driving the vehicle.

  Each of the four wheels is provided with an electric disc brake (hereinafter simply referred to as “brake”) 16 which uses the ultrasonic motor 14 as a drive source and does not use fluid pressure. Each brake 16 is selectively operated as a main brake or a parking brake. FIG. 2 representatively shows the brake 16 for one of the four wheels.

  The brake 16 includes a disk rotor 17 as a rotating body that rotates together with the wheels. Both surfaces of the disk rotor 17 are made into friction surfaces 18a and 18b, respectively, and a pair of brake pads 20a and 20b are arranged facing the friction surfaces 18a and 18b. Each brake pad 20a, 20b is provided with a friction material 22 that contacts the friction surfaces 18a, 18b on the front surface, and a steel back plate 24 is fixed to the back surface of the friction material 22.

  The brake 16 includes a pad support mechanism 26 and a pad pressurizing mechanism 28. First, the pad support mechanism 26 will be described.

  The brake 16 includes a mounting bracket 30. The mounting bracket 30 is cantilevered and fixedly attached to the vehicle body so as to straddle the disc rotor 17. The mounting bracket 30 includes: (a) a portion that supports the pair of brake pads 20a, 20b so as to be movable in a direction Y perpendicular to the friction surfaces 18a, 18b at a position sandwiching the disk rotor 17 from both sides; A portion (receiving member) for receiving a frictional force generated in each brake pad 20a, 20b when the pads 20a, 20b and the disk rotor 17 are in contact with each other is provided. That is, the mounting bracket 30 constitutes the pad support mechanism 26.

Next, the pad pressurizing mechanism 28 will be described.
The brake 16 includes a caliper 60. The caliper 60 has a structure in which a caliper main body 61 in which a pad pressing-related portion 60a, a motor mounting portion 60b, and a support portion 60c are integrated, and a motor housing 80 to be described later are separated from each other and screwed. ing. The caliper main body 61 further includes a pair of arms (not shown) each extending in parallel to the pad moving direction Y. The pair of arms are also formed integrally with the caliper main body 61.

  The caliper main body 61 is supported by the mounting bracket 30 so as to be slidable in the pad moving direction Y at the pad pressing related portion 60a. The caliper 60 is a floating type. Each arm is provided with two pins (not shown) extending in parallel with the pad moving direction Y, and these two pins are fitted to the mounting bracket 30 so as to be slidable in the pad moving direction Y. Are combined. In short, the caliper main body 61 is slidably supported by the mounting bracket 30 by the pad pressing related portion 60a and the two pins.

  The pad pressing related portion 60a includes a pressing portion 64 positioned behind the inner pad 20b of the pair of brake pads 20a, 20b, a reaction portion 66 positioned behind the outer pad 20a, and the disc rotor 17. The straddling connecting portion 68 is integrated with each other.

  A pressing piston 70 as a pressing member is fitted to the pressing portion 64 so as to be slidable behind the inner pad 20b. The pressing piston 70 is brought into contact with the back surface of the inner pad 20b on the front surface thereof. Behind the pressing piston 70, the ultrasonic motor 14 is arranged coaxially. The pressing piston 70 and the ultrasonic motor 72 are arranged coaxially with each other in parallel to the pad moving direction Y, and are connected to each other by a ball screw mechanism 74 as a motion conversion mechanism.

  The ultrasonic motor (hereinafter simply referred to as “motor”) 14 is a traveling wave type. As is well known, the motor 14 applies ultrasonic vibrations to the stator to generate surface waves, and rotates the rotor 84 by a frictional force acting between the stator 82 and the rotor 84. The motor 14 has a structure in which a stator 82 and a rotor 84 are accommodated coaxially in a bottomed cylindrical motor housing 80. The stator 82 has a structure in which an elastic body 90 and a piezoelectric body 92 are overlapped.

  The motor housing 80 has a structure in which a main body portion 80a having a through hole at the bottom and a closing portion 80b that closes the through hole are separated from each other and screwed. The motor housing 80 is screwed to the motor mounting portion 60b at the opening thereof.

  The rotor 84 is pressed against the stator 82 by the pressing contact mechanism 94 so that a necessary frictional force is obtained between the two. A friction material is bonded to a portion of the rotor 84 that contacts the stator 82. Thereby, the traveling wave vibration generated in the stator 82 is transmitted to the rotor 84 and the rotor 84 is rotated. The pressing contact mechanism 94 generates a constant frictional force between the stator 82 and the rotor 84 even in a non-energized state (OFF state) in which no voltage is applied to the piezoelectric body 92, and this frictional force causes the static holding torque to be reduced by the motor 14. Generated.

  The ball screw mechanism 74 has a structure in which a male screw member 100 and a female screw member 102 are screwed together via a plurality of balls (not shown). The male screw member 100 is restricted from rotating but is allowed to move in the axial direction, while the female screw member 102 is allowed to rotate but is restricted from moving in the axial direction.

  The male screw member 100 is non-rotatably attached to the motor housing 80 by a spline fitting portion 103. The spline fitting portion 103 is provided at a fixed position on the motor housing 80.

  A rotor 84 is attached to the female thread member 102 together with the pressing contact mechanism 94 so as not to be relatively rotatable. Therefore, if the rotor 84 rotates in the forward direction, the female screw member 102 also rotates in the normal direction. If the female screw member 102 rotates in the normal direction, the male screw member 100 moves forward (moves to the right in the drawing) and the pressing piston 70 moves to the inner side. The pad 20b moves in a direction approaching the disk rotor 17. Conversely, if the rotor 84 rotates in the reverse direction, the female screw member 102 also rotates in the reverse direction. If the female screw member 102 rotates in the reverse direction, the male screw member 100 moves backward (moves to the left in the drawing) and the pressing piston 70. However, the inner pad 20b is allowed to move away from the disk rotor 17.

  The female thread member 102 is rotatably supported by the support portion 60c of the caliper main body 61 via a radial bearing 120 and a radial thrust bearing 122 that are separated in the axial direction thereof. The female screw member 102 is fitted with a snap ring 134 as a fixing means in an annular groove formed on the outer peripheral surface thereof, and a radial bearing is formed by the snap ring 134 and the large-diameter shaft portion 135 of the female screw member 102. The axial movement of the female screw member 102 is restricted by sandwiching the motor 120, the motor mounting portion 60 b, and the radial thrust bearing 122.

  A load sensor 140 is coaxially attached to the distal end portion of the male screw member 100, and the male screw member 100 is engaged with the pressing piston 70 from the back via the load sensor 140. Therefore, based on the output signal from the load sensor 140, the applied pressure when the inner pad 20b is pressurized by the motor 14 can be detected.

  This brake system includes an operating device for a main brake. As shown in FIG. 1, the operating device includes a brake pedal 146 as a main brake operating member. The brake pedal 146 is rotatably attached to the vehicle body. A reaction force applying mechanism 148 is associated with the brake pedal 146. The reaction force applying mechanism 148 is associated with a reaction force applying mechanism 148 that applies a reaction force corresponding to the operation of the brake pedal 146 to the brake pedal 146 in association with the operation stroke of the brake pedal 146. In the reaction force applying mechanism 148, the interlocking member 150 that interlocks with the brake pedal 146 is fitted into the bottomed housing 152 so as to be slidable in the axial direction, and a compression type is provided between the bottom of the housing 152 and the interlocking member 150. The structure is provided with a spring (not shown) (see FIG. 21). The spring applies a reaction force to the brake pedal 146 in association with the operation stroke.

  The brake system further includes an operating device for a parking brake. The operating device includes a rotary PKB (parking brake) operating device 154 and a PKB (parking brake) release switch 156.

  The PKB operation device 154 replaces the parking lever or the parking pedal in the conventional mechanical parking brake device, and is provided for instructing the brake ECU 220 described later whether or not the parking brake is operated and its strength. Therefore, as shown in FIG. 3, the PKB operating device 154 is attached to the instrument panel 160 of the vehicle at a position that can be easily reached from the driver seated on the driver's seat 162. In the figure, reference numeral 164 denotes a steering wheel.

  On the other hand, the PKB release switch 156 is operated when it becomes difficult to drive the vehicle and it becomes necessary to tow the vehicle by another vehicle. The PKB release switch 156 is provided in the engine room of the vehicle. However, like the PKB operation device 154, the PKB release switch 156 can be provided at a position that can be easily reached from the driver sitting on the driver's seat 162.

Here, the structure of the PKB operation device 154 will be described in detail.
4 shows a front view of the PKB operating device 154, and FIG. 5 shows a side view. As is clear from these drawings, the PKB operating device 154 includes an attachment panel 170 attached to the instrument panel 160. A rotary type operating portion 172 is provided at a portion of the mounting panel 170 that hangs down so as to be rotatable about a single axis extending in the vehicle front-rear direction. The operation unit 172 is configured by integrally forming a long knob (knob) 174 and a circular plate 176 to be picked by the driver. The direction of the knob 174 is matched with one diameter direction of the disk 176. The direction of the upper end portion in the drawing of the both ends of the knob 174 indicates the operation position of the operation portion 172 with respect to the mounting panel 170. For this reason, the mounting panel 170 is provided with two marks respectively indicating an operation position for releasing the parking brake and an operation position for bringing the parking brake to the maximum operating state.

  The PKB operating device 154 includes a ratchet mechanism 180, a release button 182 and an automatic restoring mechanism 183, as shown in FIG. 5, in order to realize the same operation feeling as the operating device in the conventional mechanical parking brake device. It is configured as follows. When operating the operating unit 172 to increase the operating force of the parking brake, an increase in the operating angle of the operating unit 172 is allowed without any special operation, and the operating force increases as the operating angle increases. On the other hand, when operating the operation unit 172 to reduce the operating force of the parking brake, the operation angle of the operation unit 172 is decreased by the ratchet mechanism 180 unless an operation of continuously pressing the release button 182 is added. In addition, the automatic restoration mechanism 183 assists the operation unit 172 to return to the non-operation position in a state in which the operation angle is allowed to be reduced.

  The ratchet mechanism 180 is well known and will be briefly described with reference to FIG. This figure is a front view of the PKB operating device 154 and a partial cross-sectional view in which the upper part of the disk 176 is broken.

  The ratchet mechanism 180 includes a housing 185 fixed to the back surface of the mounting panel 170. A ratchet wheel 184 is fixed inside the housing 185 in parallel with the surface of the mounting panel 170. The ratchet wheel 184 is formed with a plurality of serrated teeth aligned along one circumference. Pole 186 is selectively engaged with the teeth. The pole 186 engages with the ratchet wheel 184 at its tip. Further, a rotation shaft 188 is fixed to the housing 185 in parallel with the rotation axis of the operation unit 172 of the PKB operation device 154, and the pole 186 is rotated around the rotation shaft 188.

  The release button (release operation member) 182 has an operation part 190 and a shaft part 192, and extends generally straight. The release button 182 is provided inside the knob 174 so as to be movable in parallel with the knob 174. The upper part of the operation part 190 of the release button 182 is projected from the upper end part of the knob 174 to the outside. The release button 182 is always urged by the spring 194 so as to be exposed from the knob 174 and is prevented from being detached from the knob 174 by the stopper 196. The distal end portion of the shaft portion 192 of the release button 182 is rotatably connected to the proximal end portion of the pole 186. The operation of the release button 182 allows the pole 186 to be rotated. When the release button 182 is in the original position shown in the figure, the pole 186 engages with the ratchet wheel 184, whereby the operation unit 172 is attached. Rotation in the clockwise direction (parking brake release direction) in the drawing with respect to panel 170 is prevented. On the other hand, when the release button 182 is pushed into the knob 174 against the elastic force of the spring 194, the pole 186 is separated from the ratchet wheel 184. It is allowed to rotate in the direction. Further, the driver can rotate the operation unit 172 in the counterclockwise direction (parking brake operation direction) without pressing the release button 182.

  As shown in FIG. 5, a rotation angle sensor 198 is further attached to the back surface of the attachment panel 170. The rotation angle sensor 198 includes a housing 200 and a rotor 202 rotatably attached to the housing 200, and outputs a signal corresponding to the rotation angle of the rotor 202. The rotation angle sensor 198 can be, for example, a potentiometer type. On the other hand, the shaft 204 is coaxially and integrally attached to the operation portion 172 of the PKB operation device 154 so as to be rotatable. The shaft 204 extends through the ratchet mechanism 180 to the rotor 202 and is engaged with the rotor 202 so as to be integrally rotatable. Therefore, the rotor 202 is rotated by the rotation of the operation unit 172.

  The rotation angle sensor 198 is provided with a spring 206 between the housing 200 and the rotor 202. The spring 206 constantly urges the rotor 202 toward an initial position (corresponding to a non-operation position of the operation portion 172) defined by a stopper (not shown). The elastic force of the spring 206 is transmitted to the operation unit 172 via the shaft 204. Therefore, the spring 206 functions as the automatic restoration mechanism 183.

  The mechanical configuration of the brake system has been described above. Next, the electrical configuration will be described with reference to FIG.

The brake system includes a brake electronic control unit ECU (hereinafter referred to as “brake ECU”) 220. The brake ECU 220 is configured mainly by a computer including a CPU, a ROM, and a RAM, and controls the pressure applied to the brake pads 20a and 20b by the motor 14 when the main brake is operated and when the parking brake is operated. To control. A first main battery 210 and a second main battery 212 are provided as a power source for the brake ECU 220. The first main battery 210 is provided for the left and right front wheel brake 16, and the second main battery 212 is provided for the left and right rear wheel brake 16. Thereby, unless the two main batteries 210 and 212 become abnormal together, the brake ECU 220 ensures the operation of the front wheel, the rear wheel, and at least one of the brakes 16.

  The load sensor 140 for four wheels is connected to the input side of the brake ECU 220, and the PKB release switch 156 and the rotation angle sensor 198 are connected. Furthermore, an ignition switch 222 that is operated to ignite the engine 10, a vehicle speed sensor 224 that detects the longitudinal speed of the vehicle, a wheel speed sensor 225 for four wheels that detects the rotational speed of each wheel, An acceleration sensor 226 that detects longitudinal acceleration, a yaw rate sensor 228 that detects the yaw rate of the vehicle, and a steering angle sensor 230 that detects the steering angle of the vehicle (such as the operation angle of the steering wheel 164) are also connected.

  Further, a brake pedal switch 234 that detects that the brake pedal 146 is operated and an operation stroke sensor 236 that detects an operation stroke of the brake pedal 146 are connected to the input side of the brake ECU 220. The operation stroke sensor 236 is configured to output a voltage signal corresponding to the rotation angle of the brake pedal 146. The operation stroke sensor 236 is, for example, a potentiometer type.

  On the other hand, first and second drivers 240 and 242 are connected to the output side of the brake ECU 220. The first driver 240 is provided between the first auxiliary battery 244 as a power source and the two motors 14 of the left and right front wheel brakes 16. On the other hand, the second driver 242 is provided between the second auxiliary battery 246 as a power source and the two motors 14 of the left and right rear wheel brakes 16. When the main brake is operated and when the parking brake is operated, a command is supplied from the brake ECU 220 to the drivers 240 and 242, and the drivers 240 and 242 supply power from the batteries 244 and 246 to the motors 14 in response to the commands.

  Further, on the output side of the brake ECU 220, an engine output control device (not shown) (a throttle control device, a fuel supply control device, an ignition timing control device, etc.) of the engine 10 and a transmission control device (including a shift solenoid) (not shown) of the AT 12 are provided. And are connected. The brake ECU 220 outputs a signal for suppressing the driving force to the engine output control device and the shift control device in order to suppress the spin of the driving wheel when the vehicle is driven. That is, the brake ECU 220 is also adapted to execute traction control.

  Furthermore, a brake warning device 250 is connected to the output side of the brake ECU 220. The brake warning device 250 has a form including a means for audibly alerting the driver's attention such as a buzzer, a form including a means such as a lamp for visually reminding the driver's attention, or both of them. It can be a format.

  Furthermore, a monitoring & fail detection ECU 252 is connected to the output side of the brake ECU 220. The monitoring & fail detection ECU 252 monitors the actual operating state of the electric / electronic parts related to the brake 16, and detects the failure of these electric parts based on the result. Further, when a failure is detected, a warning is given to the driver using the brake warning device 250.

  FIG. 7 is a flowchart showing a brake control routine stored in the ROM of the computer of the brake ECU 220.

If this routine is demonstrated roughly, this routine will control the brake 16 by controlling the motor 14 at the time of main brake operation and parking brake operation. During the main braking operation, it detects a main brake operating amount A _m, and the detected value, the acceleration of the vehicle, speed, yaw rate, etc., based on the detected value of the vehicle state quantity, pressurize the brake pads 20a, 20b are the motor 14 A target value of force (hereinafter, referred to as “brake pad pressing force”) is calculated, and the motor 14 is controlled while the actual pressing force is fed back by the load sensor 140 so that the target value is realized.

In consideration of the fact that the parking brake operation is performed not only when the ignition switch 222 is ON but also when the ignition switch 222 is OFF, this routine functions as a parking brake at both ON and OFF times. Let
ON the ignition switch 222 times, based on the detection value of the parking brake operating amount A _p, or a time of parking brake operation, determines whether the time that the release operation, when the parking brake operation, the parking brake operation amount A _p On the other hand, the brake pad pressure is controlled by the motor 14 based on the detected value. On the other hand, during the release operation, the motor 14 is controlled so that the brake pads 20a and 20b return from the operating position to the non-operating position. 16 is prevented from being dragged. Note that when the ignition switch 222 is turned on, the parking brake operation is not limited to being performed as intended by the driver, but may be performed contrary to the driver's intention. Therefore, if it is determined that the parking brake operation is being performed when the ignition switch 222 is turned on, this routine warns the driver.
On the other hand, when the ignition switch 222 is OFF and the PKB release switch 156 is not operated, the motor 14 is controlled so that the actual value of the brake pad pressurizing force of each wheel becomes the set value, and the PKB release is performed. When the switch 156 is operated, the motor 14 is controlled so that the action of the brake 16 is released.

  Next, the contents of this routine will be specifically described with reference to FIG. Although this routine is repeatedly executed in order for the four wheels, in order to simplify the description, the following description will be made on the assumption that this routine is repeatedly executed for the same wheel at the control cycle T.

At each execution of this routine, first, in step S1 (hereinafter simply referred to as S1, the same applies to other steps), it is determined whether or not the ignition switch 222 is ON, that is, the vehicle travel start command is issued by the driver. Whether or not is issued is determined. If it is assumed that it is ON this time, the determination is YES, and in S2, the flags F ₁ and F ₂ provided in the RAM are both set to 0. The function of these flags will be described later. Subsequently, in S3, it is determined whether or not the brake pedal switch 234 is OFF, that is, whether or not the main brake is being operated. Assuming this time is OFF, the determination is YES, in S4, the parking brake operating amount A _P is detected as the operation angle of the operating unit 172 by the rotational angle sensor 198 of PKB operating device 154. Thereafter, in S5, it is determined whether or not the detected value of the parking brake operation amount _AP is equal to or greater than a reference value A0 that is slightly larger than _zero . Unless the detection value of the parking brake operating amount A _P is not 0, if it is determined that the current parking brake operation is being performed is actually deviated slightly from unintended despite detection value driver 0 Considering that the parking brake may occur, the parking brake is operated against the driver's intention. Accordingly, in the sense to have a play in the detection value of the parking brake operating amount A _P, whether the detected value of the parking brake operating amount A _P is the reference value A ₀ or more is determined, it is the reference value A ₀ or more In this case, the determination is YES, which indicates that it is determined that a substantial parking brake operation is being performed. Assuming that it is not the reference value A ₀ or more time, a negative decision (NO) is obtained in S6, the brake pad pressing force F _fr of each wheel, F _fl, F _rr, the target value of F _rl is for all the brakes 16 Calculation is performed so that the drag of all the brakes 16 is set to 0 while being released. Specifically, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are all set to zero. Thereafter, in S7, each motor 14 is controlled so that each calculated target value is realized. This completes one execution of this routine.

On the other hand, if it is assumed that the detected value of the parking brake operation amount A _P is greater than or equal to the reference value A ₀ , the determination in S5 is YES, and in S8, the brake pad pressures F _fr , F _fl , F _rr, the target value of F _rl is calculated as a magnitude corresponding to the parking brake operating amount a _m. Specifically, the target value of the brake pad pressure F _fr of the right front wheel FR is
F _fr = K _f · A _m
The target value of the brake pad pressure F _fl for the left front wheel FL is
F _fl = K _f · A _m
The target value of the brake pad pressure F _rr for the right rear wheel RR is
F _rr = K _r · A _m
The target value of the brake pad pressure F _rl for the left rear wheel RL is
F _rl = K _r · A _m
Are calculated by the following expressions. In these equations, “K _f ” is a coefficient for left and right front wheels, and “K _r ” is a coefficient for left and right rear wheels.

  Thereafter, in S9, each motor 14 is controlled so that each calculated target value is realized. Subsequently, at S10, the brake warning device 250 is activated, thereby notifying the driver that the parking brake is currently being operated. Thereby, it can be noticed that a parking brake operation unintended by the driver is being performed. This completes one execution of this routine.

  As for the operation mode of the brake warning device 250, when the brake warning device 250 has both a lamp and a buzzer, the vehicle is warned to the driver by operating both the lamp and the buzzer when the vehicle travels. At the time of stop, only the lamp can be operated to warn the driver. In general, the intensity of alerting the driver's attention is stronger in the buzzer than in the ramp, while the possibility that the parking brake operation being performed is contrary to the driver's intention is when the vehicle is running and when the vehicle is stopped. Greater than. Therefore, when the parking brake operation is performed with the ignition switch 222 being ON, the driver can be warned strongly when the vehicle is traveling and weakly when the vehicle is stopped.

  The case where the ignition switch 222 is ON and the brake pedal switch 234 is OFF has been described above. Hereinafter, the case where both the ignition switch 222 and the brake pedal switch 234 are ON will be described.

In this case, the determination of S1 is YES, the determination of S3 is NO, and the process proceeds to S11 and below. In S11, it is detected as an operation stroke of the brake pedal 146 main brake operating amount A _m is the operation stroke sensor 236. Thereafter, in S12, detection values of various sensors are input. Specifically, a detected value of acceleration G by acceleration sensor 226, a detected value of vehicle speed V by vehicle speed sensor 224, and a detected value of yaw rate γ by yaw rate sensor 228 are input. Subsequently, in S13, the target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl for each wheel are the main brake operation amount A _P and the actual value of the vehicle motion state quantity, that is, the acceleration G. According to the detected value, the detected value of the vehicle speed V, and the detected value of the yaw rate γ, the driver's intention is reflected and the calculation is performed so that the vehicle behavior does not become unstable. Specifically, the target value of the brake pad pressure F _fr of the right front wheel FR is
F _fr = K _fr (G, V, γ) · A _P
The target value of the brake pad pressure F _fl for the left front wheel FL is
F _fl = K _fl (G, V, γ) · A _P
The target value of the brake pad pressure F _rr for the right rear wheel RR is
F _rr = K _rr (G, V, γ) · A _P
The target value of the brake pad pressure F _rl for the left rear wheel RL is
F _rl = K _rl (G, V, γ) · A _P
Are calculated by the following expressions. In these equations, “K _fr (G, V, γ)”, “K _fl (G, V, γ)”, “K _rr (G, V, γ)” and “K _rl (G, V, γ)” Are the coefficients for the right front wheel FR, the left front wheel FL, the right rear wheel RR, and the left rear wheel RL, respectively, all of which are expressed as functions with acceleration G, vehicle speed V, and yaw rate γ as variables. Has been.

  Thereafter, in S14, each motor 14 is controlled so that each calculated target value is realized. This completes one execution of this routine.

  The case where the ignition switch 222 is ON has been described above, but the case where it is OFF will be described below.

In this case, the determination in S1 is NO, and the process proceeds to S15 and below. In S15, it is determined whether or not the PKB release switch 156 is ON. Assuming this time is OFF, the determination is NO, in S16, the flag F ₁ is determined whether it is 1. Since it is 0 this time, the determination is no, and in S17, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are calculated so that the vehicle is maintained in a stopped state. The Specifically, the target values of the brake pad pressures F _fr and F _{fl for} the right front wheel FR and the left front wheel FL are both set to a set value FF (a constant value), and the brakes for the right rear wheel RR and the left rear wheel RL are set. The target values of the pad pressures F _rr and F _rl are both calculated to a set value FR (constant value). Thereafter, in S18, each motor 14 is controlled so that each calculated target value is realized. Subsequently, in S19, each motor 14 is turned off. As a result, a stationary holding torque is generated in each motor 14, and the vehicle is maintained in a stopped state by the stationary holding torque. Thereafter, in S20, the flag F ₁ is set to 1 and the flag F ₂ is set to 0. This completes one execution of this routine.

Thereafter, this routine is executed again. At this time, if it is assumed that the ignition switch 222 is still ON and the PKB release switch 156 is OFF, the flag F ₁ is 1 this time, so the determination of S16 is YES, S17 to S20 are skipped. Unless it is necessary to change the brake pad pressure (corresponding to the actual operating force of the parking brake), power supply to the motor 14 is blocked, thereby reducing power consumption.

Thereafter, assuming that the PKB release switch 156 is turned on, the determination in S15 is YES, and in S21, it is determined whether or not the flag F ₂ is 1. Since this time is 0, the determination is NO, and in S22, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are calculated so that each brake 16 is released. . Specifically, the target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl for all the wheels are all calculated as zero. Thereafter, in S23, each motor 14 is controlled so that each calculated target value is realized. Subsequently, in S24, each motor 14 is turned off. Each motor 14 is restored to a non-operating state. Thereafter, in S25, the flag F ₁ is set to 0 and the flag F ₂ is set to 1. This completes one execution of this routine.

Thereafter, this routine is executed again. At this time, if it is assumed that the ignition switch 222 is still ON and the PKB release switch 156 is also ON, the flag F ₂ is 1 this time, so the determination in S21 is YES, S22 to S25 are skipped. As long as it is not necessary to change the brake pad pressure, power supply to the motor 14 is blocked, thereby reducing the amount of power consumption.

  As is clear from the above description, in the present embodiment, the engine 10 corresponds to a “power source”, the ignition switch 222 corresponds to a “power source switch”, the brake 16 corresponds to a “parking brake”, The motor 14 corresponds to an “electric motor”, the stationary holding torque generation mechanism of the motor 14 corresponds to an “operating force holding mechanism”, and among the PKB operating device 154, the PKB release switch 156, and the brake ECU 220, S1 and S15 in FIG. -S25 and the part that executes S25 together constitute a "parking brake control device", of which PKB release switch 156 and brake ECU 220 execute S1, S15, and S21-S24 in the same figure. It constitutes a “power change device”. Further, the PKB release switch 156 corresponds to a “parking brake release switch”, and the portion of the brake ECU 220 that executes S1, S15, and S21 to S24 in FIG. 7 constitutes “first motor control means”. .

  Next, a second embodiment of the present invention will be described. However, since this embodiment has many elements in common with the previous first embodiment, and only the brake control routine is different, only the routine will be described in detail, and the same reference numerals are used for the common elements. Therefore, detailed description is omitted.

  The brake control routine in the present embodiment basically has the same design concept as the brake control routine in the first embodiment. However, there are different design ideas. The outline will be described below.

  In the brake control routine according to the first embodiment, when the ignition switch 222 is OFF, the electric parking brake is released regardless of the timing, and the electric parking brake is released (the brake 16 is turned into the parking brake). When the operation of the PKB release switch 156 is released, the electric parking brake is activated. On the other hand, in the brake control routine in this embodiment, in order to prevent the electric parking brake from being released due to an erroneous operation of the PKB release switch 156, at the same time as the PKB release switch 156 is operated, When another switch is operated, that is, when the ignition switch 222 is turned off, the electric parking brake is released. Specifically, even if the PKB release switch 156 is operated at a time other than the time when the ignition switch 222 is operated from ON to OFF, it is ignored by the brake ECU 220.

  Furthermore, the brake control routine in the present embodiment is designed such that the power consumption of the brake ECU 220 is less than that in the first embodiment. In the first embodiment, when it is not necessary to change the pressure applied to the brake pad, as shown in FIG. 7, S1 and S15 are executed at each execution of the brake control routine when the ignition switch 222 is OFF. There are cases where S16 and S16 are executed, and cases where S1, S15 and S21 are executed. In either case, three steps are executed. On the other hand, in this embodiment, only two steps, that is, only S51 and S65 shown in FIG. 8, are executed at each execution of the brake control routine when the ignition switch 222 is OFF. Designed. Thereby, the power consumption of the brake ECU 220 when the ignition switch 222 is OFF is made smaller than in the first embodiment. Hereinafter, a mode in which only S51 and S65 are executed at each execution of the brake control routine is referred to as an ECU energy saving mode.

  FIG. 8 is a flowchart showing the brake control routine in the present embodiment. Hereinafter, although this routine will be described, since there are many steps common to the brake control routine in the first embodiment, only different steps will be described in detail.

  As in the first embodiment, this routine is repeatedly executed at extremely short time intervals (for example, 5 to 10 ms). When executing each time, first, in S51, it is determined whether or not the ignition switch 222 is ON. If it is assumed that it is ON, the determination is YES, and the ECU energy saving mode is canceled in S52. Thereafter, S53 to S64 are executed in the same manner as S3 to S14 in FIG. This completes one execution of this routine.

  On the other hand, if it is assumed that the ignition switch 222 is OFF this time, the determination in S51 is NO, and it is determined in S65 whether or not the ignition switch 222 was OFF during the previous execution of this routine. . If it is assumed that the ignition switch 222 was ON at the previous execution, the determination is NO, and it is determined in S66 whether the PKB release switch 156 is ON. If it is assumed that it is OFF this time, the determination is no and S67 to S69 are executed in the same manner as S17 to S19 in FIG. As a result, the brake 16 is operated as a parking brake, and the vehicle is maintained in a stopped state. Thereafter, in S70, an ECU energy saving mode is established. This completes one execution of this routine.

  On the other hand, if it is assumed that the ignition switch 222 is operated from ON to OFF and the PKB release switch 156 is operated from OFF to ON at the same time, the ignition switch 222 is OFF and the previous time of this routine is changed. At the time of execution, since the ignition switch 222 is ON and the PKB release switch 156 is ON, the determination of S51 is NO, the determination of S65 is NO, the determination of S66 is YES, and S71 to S73 are S22 in FIG. To S24. As a result, the brake 16 is released from operating as a parking brake, and the vehicle shifts to a state where it can start. Thereafter, in S74, the ECU energy saving mode is established. This completes one execution of this routine.

  If it is assumed that the ignition switch 222 was OFF at the previous execution of this routine, the determination at S51 is NO and the determination at S65 is YES, and one execution of this routine is immediately terminated. Thereafter, as long as the ignition switch 222 is OFF, only S51 and S65 are executed at each execution of this routine, thereby reducing the power consumption of the brake ECU 220.

  In the present embodiment, the PKB release switch 156 is turned ON simultaneously with the ignition switch 222 being turned OFF, and as a result, the ignition switch 222 is not turned ON after the parking brake is released. As long as the parking brake cannot be activated. On the other hand, if a mechanical emergency brake is provided in the brake system, the vehicle can be parked even after the ignition switch 222 is turned off and the PKB release switch 156 is turned on at the same time. It becomes possible. For example, a drum brake that is mechanically actuated by an emergency brake operation member (pedal or lever) can be employed as the mechanical emergency brake.

  As is apparent from the above description, in the present embodiment, the PKB operating device 154, the PKB release switch 156, and the portion of the brake ECU 220 that executes S51 and S65 to S74 in FIG. Of the PKB release switch 156 and the brake ECU 220, the part that executes S51, S66, and S71 to S74 in the figure constitutes the “actual operating force change device”. Further, the PKB release switch 156 corresponds to a “parking brake release switch”, and the portion of the brake ECU 220 that executes S51, S65, and S71 to S73 of FIG. 8 constitutes “first motor control means”. .

  Next, a third embodiment of the present invention will be described. However, this embodiment has many elements in common with the first embodiment, and the difference is the brake control routine and the electrical configuration related thereto, so only the different elements will be described in detail, and the common elements will be the same. Detailed description will be omitted by using reference numerals.

  In the first embodiment, when the PKB operating device 154 is operated while the ignition switch 222 is ON, all four brakes 16 are operated as parking brakes. On the other hand, in the present embodiment, the driver can switch between a state in which all four brakes 16 operate as parking brakes and a state in which only the rear two brakes 16 operate as parking brakes. Yes. Therefore, as shown in FIG. 9, a PKB (parking brake) changeover switch 300 is added to the first embodiment. The PKB changeover switch 300 has a first operation position that realizes a state in which all four brakes 16 operate as parking brakes, and a second operation position that realizes a state in which only the rear two wheel brakes 16 operate as parking brakes. Can be switched to.

In FIG. 10, a modified version of S8 in the first embodiment is shown in a flowchart as a brake pad pressure calculation routine. In this routine, first, in S101, it is determined whether the current operation position of the PKB changeover switch 300 is the first operation position or the second operation position. Assuming that it is the first operation position, in S102, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are set so that all the four-wheel brakes 16 operate as parking brakes. Is calculated. Specifically, the target value of the brake pad pressure F _fr of the right front wheel FR is
F _fr = K _f0 · A _P
The target value of the brake pad pressure F _fl for the left front wheel FL is
F _fl = K _f0・ A _P
The target value of the brake pad pressure F _rr for the right rear wheel RR is
F _rr = K _r1・ A _P
The target value of the brake pad pressure F _rl for the left rear wheel RL is
F _rl = K _r1 · A _P
Are calculated by the following expressions. In these equations, “K _f0 ” is a coefficient for left and right front wheels, and “K _r1 ” is a coefficient for left and right rear wheels.

On the other hand, if it is assumed that the current operation position of the PKB changeover switch 300 is the second operation position, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are assumed in S103. However, the calculation is performed so that only the rear two-wheel brake 16 operates as a parking brake. Specifically, the target value of the brake pad pressure F _fr of the right front wheel FR and the target value of the brake pad pressure F _fl of the left front wheel FL are both calculated to be 0, and the right rear wheel RR is calculated. The target value of the brake pad pressure F _rr is
F _rr = K _r2 · A _P
The target value of the brake pad pressure F _rl for the left rear wheel RL is
F _rl = K _r2 · A _P
Are calculated by the following expressions. In these equations, “K _r2 ” is a coefficient for the left and right rear wheels.

  As is clear from the above description, in the present embodiment, the PKB changeover switch 300 and the portion of the brake ECU 220 that executes S101 to S103 in FIG. 10 jointly constitute a “combination changing device”. It is.

  11 to 13 show another modification of the brake pad pressure calculation routine. In the brake pad pressure calculation routine shown in FIG. 10, among the four wheels, the mode in which the brake 16 is operated as a parking brake is manually switched between the mode for all four wheels and the mode for only the rear two wheels. However, in the three modified examples shown in FIGS. 11 to 13, they are automatically switched. In these three modifications, the parking brake operation performed with the ignition switch 222 being ON is considered to be performed by the driver trying to spin-turn the vehicle. The steering operation necessary for spin-turning the vehicle in conjunction with the operation of the brake 16 of the vehicle and the vehicle state generally realized when such a spin-turn is performed are detected and detected. When this occurs, only the rear two-wheel brake 16 is activated, thereby inducing a side slip of the rear two wheels in conjunction with the steering operation.

Specifically, in the brake pad pressure calculation routine shown in FIG. 11, in S121, the steering angle δ is detected by the steering angle sensor 230, and it is determined whether or not the detected value is equal to or greater than the reference value K. Is done. If it is not the reference value K or more, the determination is NO, and in S122, the target values of the brake pad pressurizing forces F _fr , F _fl , F _rr , F _rl are set to 4 brakes 16 as in S102 in FIG. It is calculated to operate as a parking brake. On the other hand, if the detected value of the steering angle δ is greater than or equal to the reference value K, the determination in S121 is YES, and in S123, the brake pad pressures F _fr , F _fl , F _rr are the same as S103 in FIG. , F _rl is calculated so that only the rear two-wheel brake 16 operates as a parking brake.

  In other words, in the present modification, the steering angle sensor 230 and the part of the brake ECU 220 that executes S121 to S123 in FIG. 11 jointly constitute a “combination changing device”.

In the brake pad pressure calculation routine shown in FIG. 12, the vehicle speed sensor 224 detects the vehicle speed V and determines whether or not the detected value is greater than or equal to a reference value L in S141. If the reference value is not equal to or greater than the reference value L, the determination is NO, and the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl are determined in S142 as in S102 in FIG. It is calculated to operate as a parking brake. On the other hand, if the detected value of the vehicle speed V is greater than or equal to the reference value L, the determination in S141 is YES, and in S143, the brake pad pressures F _fr , F _fl , F _rr are the same as S103 in FIG. , F _rl is calculated so that only the rear two-wheel brake 16 operates as a parking brake.

  In other words, in the present modification, the vehicle speed sensor 224 and the portion of the brake ECU 220 that executes S141 to S143 in FIG. 12 jointly constitute a “combination changing device”.

In the brake pad pressure calculation routine shown in FIG. 13, the steering angle δ is detected by the steering angle sensor 230 in S161. Subsequently, in S162, a value obtained by subtracting the previous value from the current value of the detected value is calculated in this routine. The steering angular velocity dδ is calculated by dividing by the execution period of. Thereafter, in S163, it is determined whether or not the calculated steering angular velocity dδ is equal to or greater than a reference value M. If it is not greater than the reference value M, the determination is NO, and in S164, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl are set to 4 brakes 16 as in S102 in FIG. It is calculated to operate as a parking brake. On the other hand, if the calculated steering angular speed dδ is equal to or greater than the reference value M, the determination in S164 is YES, and in S165, the brake pad pressures F _fr , F _fl , F _rr are the same as S103 in FIG. , F _rl is calculated so that only the rear two-wheel brake 16 operates as a parking brake.

  That is, in the present modification, the steering angle sensor 234 and the portion of the brake ECU 220 that executes S161 to S165 of FIG. 13 cooperate to constitute a “combination changing device”.

  The brake pad pressure calculation routine shown in FIGS. 10 to 13 can be a modified example of S58 of the brake control routine in the second embodiment.

  Next, a fourth embodiment of the present invention will be described. However, since this embodiment has many elements in common with the first embodiment, and only the brake control routine and the electrical configuration related thereto are different, only the different elements will be described in detail, and the common elements are the same. Detailed description will be omitted by using the reference numeral.

In the first embodiment, the four-wheel brake 16 is operated as a parking brake in response to the operation of the ignition switch 222 from ON to OFF. At this time, the brake pad pressure is constant. The motor 14 is controlled so as to be maintained at a set value which is a value. In contrast, in the present embodiment, the brake pad pressure is maintained at a set value that is a variable value, and the set value is changed according to the inclination angle θ _R of the road surface on which the vehicle is parked. Specifically, as shown in the graph of FIG. 16, the setting value FF for the left and right front wheels is larger than the setting value FR for the left and right rear wheels, and both of the setting values FF and FR have the inclination angle θ _{R of the} road surface. It is changed to increase as it increases. In order to change the set values FF and FR according to the inclination angle θ _R in this way, as shown in FIG. 14, an inclination angle sensor 320 is added to the first embodiment. The inclination angle sensor 320 is, for example, a weight type that detects the inclination angle θ _{R of the} road surface as an angle formed by a vertical axis fixed to the vehicle and a weight that is rotatably attached in one plane including the vertical axis. be able to.

FIG. 15 is a flowchart showing a brake pad pressure calculation routine obtained by modifying S17 in the first embodiment. In this routine, first, in S201, the road surface inclination angle θ _R is detected by the inclination angle sensor 320. Next, in S202, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are calculated so as to increase according to the road surface inclination angle θ _R. Specifically, the target value for the brake pad pressure F _{fr for} the right front wheel FR and the target value for the brake pad pressure F _{fl for} the left front wheel FL are:
F _fr = FF (θ _R )
F _fl = FF (θ _R )
The target value of the brake pad pressure F _rr for the right rear wheel RR and the target value of the brake pad pressure F _{rl for} the left rear wheel RL are:
F _rr = FR (θ _R )
F _rl = FR (θ _R )
Are calculated by the following expressions. In these equations, “FF (θ _R )” is a coefficient for the left and right front wheels, and is expressed as a function with the road surface inclination angle θ _R as a variable. “FR (θ _R )” It is a coefficient for the wheel and is expressed as a function with the road surface inclination angle θ _R as a variable.

  Note that the brake pad pressure calculation routine shown in this figure can be a modified example of S67 of the brake control routine in the second embodiment.

  Next, a fifth embodiment of the present invention will be described. However, this embodiment has many elements in common with the first embodiment, and only the brake control routine is different. Therefore, only the routine will be described in detail, and the same reference numerals will be used for other common elements. Therefore, detailed description is omitted.

  In the first embodiment, the four-wheel brake 16 is operated as a parking brake in response to the operation of the ignition switch 222 from ON to OFF. At this time, the brake pad pressure is constant. The motor 14 is controlled so as to be maintained at a set value which is a value. In contrast, in the present embodiment, the brake pad pressure is maintained at a set value that is a variable value, and the set value is an initial value that is a constant value so that the vehicle is actually maintained in a stopped state. Increased from and determined. By setting the brake pad pressure as the initial value as the set value, if the vehicle cannot be actually stopped, the set value is increased until the vehicle is stopped.

  In FIG. 17, a modified version of S17 in the first embodiment is represented by a flowchart as a brake pad pressure calculation routine.

In this routine, first, in S221, the target values of the brake pad pressures F _fr and F _{fl for} the right front wheel FR and the left front wheel FL are all set to the initial value FF ₀ (constant value), the right rear wheel RR and the left rear wheel The target values of the brake pad pressures F _rr and F _rl with the wheel RL are both calculated to the initial value FR ₀ (constant value). Next, in S222, each motor 14 is controlled so that each calculated target value is realized. Thereafter, in S223, the vehicle speed V is detected by the vehicle speed sensor 224. Subsequently, in S224, based on the detected vehicle speed V, it is determined whether or not the vehicle is actually stopped. For example, if the detected vehicle speed V is less than or equal to a reference value close to 0, it is determined that the vehicle is actually in a stopped state, and if it is greater than the reference value, it is determined that the vehicle is actually in a running state. If it is assumed that the vehicle is stopped this time, one execution of this routine is immediately terminated. On the other hand, if it is assumed that the vehicle is not stopped this time, the determination in S224 is NO, and in S225, the target values of the brake pad pressures F _fr and F _{fl for} the right front wheel FR and the left front wheel FL are both. The target value of the brake pad pressures F _rr and F _{rl for} the right rear wheel RR and the left rear wheel RL is both increased by an increment ΔFR (constant value). Thereafter, the process returns to S222.

  If the determination in S224 is YES because the vehicle has been stopped while the execution of S222 to S225 is repeated, one execution of this routine ends.

  Note that the brake pad pressure calculation routine shown in this figure can be a modified example of S67 of the brake control routine in the second embodiment.

  Next, a sixth embodiment of the present invention will be described. However, this embodiment has many elements in common with the first embodiment, and only the brake control routine is different. Therefore, only the routine will be described in detail, and the same reference numerals will be used for other common elements. Therefore, detailed description is omitted.

In the first embodiment, in order to release the parking brake while the ignition switch 222 is ON, the operation unit 172 of the PKB operation device 154 is moved from the operation position tilted to the right in FIG. It is necessary to rotate. Therefore, as shown by a broken line graph in FIG. 19, at the beginning of the release operation, the brake pad pressure F decreases in accordance with a decrease in the parking brake operation amount A _P (the rotation angle of the operation unit 172). On the other hand, when the conventional mechanical parking brake device is used, when the parking brake is released, the parking brake operating member functions as a switch by the automatic restoration mechanism, and as a result, the brake pad pressure F decreases rapidly. Therefore, in the present embodiment, in order to achieve an operation feeling equivalent to that of a conventional mechanical parking brake device, first, after the ignition switch 222 is operated from OFF to ON, as shown by a solid line graph in the drawing, by the time the parking brake operating amount a _P is reduced to the reference value a _0, i.e., before the parking brake release of the first time, the brake pad pressing force F is held without being allowed to follow the change of the parking brake operating amount a _P, After the parking brake operation amount A _P decreases to the reference value A ₀ , the motor 14 is controlled so that the brake pad pressure F suddenly becomes zero. By doing so, PKB operation device 154 is operated to continuously change the parking brake operating amount A _P, before the driver to command the parking brake release of the first time, it functions as a switch become.

  FIG. 18 is a flowchart showing a brake pad pressure calculation routine obtained by modifying S8 in the first embodiment.

In this routine, first, in S241, it is determined whether or not the first parking brake is released after the ignition switch 222 is operated from OFF to ON. If so, the determination is YES, and in S242, as in S17 in the first embodiment, the target values of the left and right front wheel brake pad pressures F _fr and F _fl are the set value FF, and the left and right rear wheel brake pads. The target values of the applied pressures F _rr and F _rl are calculated so as to be equal to the set value FR. On the other hand, if it is after the first release of the parking brake after the ignition switch 222 is operated from OFF to ON, the determination in S241 is NO, and in S243, similar to S8 in the first embodiment. The target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl for each wheel are calculated so as to have a magnitude corresponding to the parking brake operation amount A _P.

In S242, the target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl for each wheel are calculated in the same manner as the brake pad pressure calculation routine in FIG. 15 or FIG. it can.

  Further, the brake pad pressure calculation routine shown in FIG. 18 can be a modified example of S58 of the brake control routine in the second embodiment.

  Next, a seventh embodiment of the present invention will be described. However, this embodiment has many elements in common with the first embodiment, and only the brake control routine is different. Therefore, only the routine will be described in detail, and the same reference numerals will be used for other common elements. Therefore, detailed description is omitted.

  In the first embodiment, after the ignition switch 222 is operated from ON to OFF, the brake pad pressure F cannot be changed according to the driver's intention. On the other hand, in this embodiment, if the PKB operation device 154 is operated for a set time (for example, 3 to 10 minutes) from the time when the ignition switch 222 is operated from ON to OFF, F can be changed. The final time when the brake pad pressure F can be changed by the PKB operating device 154 according to the driver's intention is set to be later than the time when the ignition switch 222 is operated from ON to OFF. Therefore, the usability of the parking brake is improved as compared with the first embodiment in which the brake pad pressure F cannot be changed after the ignition switch 222 is operated from ON to OFF. Hereinafter, control for delaying the final time when the brake pad pressure F can be changed by the PKB operating device 154 according to the driver's intention from the time when the ignition switch 222 is operated from ON to OFF is referred to as “delay”.

  FIG. 20 is a flowchart showing the brake control routine in the present embodiment. This routine includes steps common to S15 to S25 in the brake control routine in the first embodiment, but also includes different steps. Hereinafter, although this routine will be described, the same reference numerals are used for steps common to the brake control routine in the first embodiment, and detailed description thereof will be omitted, and only different steps will be described in detail.

  If the ignition switch 222 is OFF, the determination in S1 is NO, and the process proceeds to S301 and subsequent steps. In S301, it is determined whether or not the delay end flag is 1. The delay end flag is 0 to indicate that the delay has not ended, that is, the delay is in progress, and 1 indicates that the delay has ended. This delay end flag is set to 0 when the determination of S1 finally changes from YES to NO.

Assuming that this time delay completion flag is 0, it is detected S301 the determination is NO, and in S302, the operation angle of the operation portion 172 by the rotation angle sensor 198 of the parking brake operating amount A _P is PKB operation device 154 together, the detected value whether or not the reference value A ₀ or not is determined. It is determined whether or not a substantial parking brake operation is being performed.

Assuming that it is not the reference value A ₀ or more time, a negative decision (NO) is obtained in S303, the brake warning device 250 is activated. This is to inform the driver that the parking brake operation, which is generally performed when the ignition switch 222 is OFF, is not performed. Thereafter, in S304, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are calculated so as to increase according to the parking brake operation amount A _P. Since it is assumed that the parking brake operation amount A _P is smaller than the reference value A ₀ this time, the target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl of each wheel are all set to 0. . Thereafter, in S305, each motor 14 is controlled so that the calculated target value is realized. Eventually, the actual value of the brake pad pressure F is set to 0 this time, thereby releasing the brake 16.

On the other hand, if it is assumed that the parking brake operation amount A _P is greater than or equal to the reference value A ₀ this time, the determination in S302 is YES, and in S306, the brake warning device 250 is turned off. A signal is output. Thereafter, in S304, the target values of the brake pad pressures F _fr , F _fl , F _rr , F _rl of each wheel are calculated so as to increase according to the parking brake operation amount A _P. Since it is assumed that the parking brake operation amount A _P is greater than or equal to the reference value A ₀ this time, the target values of the brake pad pressures F _fr , F _fl , F _rr , and F _rl for each wheel are all greater than zero. Value. Thereafter, in S305, each motor 14 is controlled so that the calculated target value is realized. Eventually, the actual value of the brake pad pressure F is set to a non-zero value this time, and the brake 16 is operated accordingly.

  In any case, after that, in S307, it is determined whether or not the set time has elapsed since the ignition switch 222 was last operated from ON to OFF. It is determined whether it is time to end the delay. If it is assumed that the set time has not elapsed this time, the determination is no and a signal for setting the delay end flag to 0 is output in S308. If this routine is subsequently executed, the determination in S301 is NO, so that the brake pad pressure F can be freely set by the PKB operating device 154 while the ignition switch 222 is OFF, as in the above case. Can change.

  Since the execution of S1 and S301 to S308 has been repeated many times, if the set time has elapsed since the ignition switch 222 was last operated from ON to OFF, the determination in S307 becomes YES, and in S309, the motor 14 is turned off. The vehicle is parked by the stationary holding torque of the motor 14. Thereafter, in S310, the delay end flag is set to 1. If this routine is subsequently executed, the determination in S301 is YES, and one execution of this routine is immediately terminated. That is, after the end of the delay, only S1 and S301 of the plurality of steps of this routine are executed, thereby reducing the amount of power consumed by the brake ECU 220.

  The brake ECU 220 is in the ECU energy saving mode when the delay end flag is 1, and the ECU energy saving mode is canceled when the brake ECU 220 is 0. Therefore, the delay end flag is used to establish / release the ECU energy saving mode. It can be said that this is a flag representing.

  As is clear from the above description, in the present embodiment, the PKB operation device 154 and the portion of the brake ECU 220 that executes S304 in FIG. 20 together constitute a “manual target operating force setting device”. The portion of the brake ECU 220 that executes S305 in the figure constitutes “second motor control means”. Further, the portion of the brake ECU 220 that executes S301 and S307 to S310 in the figure constitutes “power supply blocking means”.

  In the present embodiment, the set time, that is, the delay time is set to a constant value, but may be a variable value that can be changed by the driver.

  Next, an eighth embodiment of the present invention will be described. However, since this embodiment has many elements in common with the first embodiment, and only the elements related to the technique for detecting the operation stroke of the brake pedal 146 are different, the elements will be described in detail and other elements will be described. Detailed description will be omitted by using the same reference numerals.

  FIG. 21 shows the brake pedal 146 and the mechanical structure associated therewith. The brake pedal 146 is attached to the vehicle body at a base end portion of the brake pedal 146 so as to be rotatable around a single axis extending in the left-right direction of the vehicle. An intermediate portion of the brake pedal 146 is rotatably connected to a distal end portion of the interlocking member 150 of the reaction force applying mechanism 148 via a clevis 338. The brake pedal 146 is always urged toward the non-operating position by the return spring 340, while being prevented from rotating counterclockwise in the figure from the non-operating position by the stopper 342. The stopper 342 is attached to the vehicle body by a fixture 344. The fixture 344 has a mechanism for adjusting the position where the stopper 342 contacts the brake pedal 146 by a screw mechanism or the like. The brake pedal switch 234 outputs a different signal depending on whether or not the brake pedal 146 is in the non-operation position.

  In order to detect the operation stroke of the brake pedal 146, the operation stroke detection device 350 is attached coaxially with the rotation axis of the brake pedal 146. The operation stroke detection device 350 detects the rotation angle of the brake pedal 146 as the operation stroke of the brake pedal 146.

  At the time of assembling the vehicle, the adjusting mechanism of the mounting tool 344 adjusts the non-operating position of the brake pedal 146 to the normal position. However, the actual non-operation position may deviate from the normal position. In this case, the operation stroke detection device 350 does not coincide with the zero point at the actual non-operation position. In spite of such a case, the brake ECU 220 controls the brake pad pressurizing force on the assumption that the zero point of the operation stroke detection device 350 coincides with the actual non-operation position. May feel uncomfortable. Therefore, in this embodiment, the zero point adjustment of the operation stroke detection device 350 is performed. In the actual non-operating position of the brake pedal 146, that is, when the brake pedal switch 234 changes from OFF to ON, the operation stroke detected by the operation stroke detection device 350 is set as an error value, and the operation position of the brake pedal 146 is determined. In other words, when the brake pedal switch 234 is ON, the operation stroke detected by the operation stroke detector 350 is not used as it is, but the error value is subtracted and used.

  When the operation stroke detection device 350 is configured to have only one operation stroke sensor, if the operation stroke sensor fails, the operation stroke cannot be detected, and thus the brake pad pressure is controlled. Can not. Therefore, in the present embodiment, the operation stroke detection device 350 has three operation stroke sensors, that is, a first sensor 352, a second sensor 354, and a third sensor 356, as shown in FIG. It is set as the structure arrange | positioned along with the axis of rotation coaxially. It is rare that the three sensors 352, 354, and 356 fail at the same time, and it is considered rare that two of them fail at the same time. Therefore, at least two of the three sensors 352, 354, and 356 can be considered to be normal at the same time, and if it can be considered in this way, any two of the three sensors 352, 354, and 356 can be If the difference between the output signals is extracted and the absolute value of the difference is 0, the two sensors corresponding to the difference are both normal, while if the absolute value of the difference is not 0, It can be estimated that one of the two sensors corresponding to the difference fails and the other is normal. Therefore, in the present embodiment, extracting the two arbitrarily from these three sensors 352, 354, 356 and taking the difference of the output signals is continued until the absolute value of the difference occurs to be zero, When the absolute value of the difference becomes 0, the operation stroke is calculated based on the output signal of either of the two sensors corresponding to the difference. Therefore, according to the present embodiment, it is possible to avoid a situation in which the operation stroke cannot be detected due to the failure of the operation stroke sensor. Such an operation detection technique is based on the fact that the majority sensor is applied to the three detection values, so that two sensors having the same detection value are both normal, but the remaining sensors are abnormal. It can also be considered that this is done based on

  FIG. 23 is a flowchart showing an operation stroke detection routine stored in the ROM of the brake ECU 220 in this embodiment.

  In this routine, first, in S401, it is determined whether or not the brake pedal switch 234 is ON. If it is assumed that it is OFF, the determination is NO, and a signal for setting the flag F to 0 is output in S402. This completes one execution of this routine.

Thereafter, when the operation of the brake pedal 146 is started and the brake pedal switch 234 changes from OFF to ON, the determination in S401 becomes YES, and in S403, the detected values (raw values) S _{S of the} sensors 352, 354, and 356 1, S _S 2 and S _S 3 are input. Thereafter, in S404, it is determined whether or not the flag F is 0. Because this is the 0, the determination is YES, in S405, the detected value S _S 1 of the first sensor 352 is the error value S _e 1 of the first sensor 352, the detected value S _S 2 of the second sensor 354 second The error S _e 2 of the sensor 354 and the detection value S _S 3 of the third sensor 356 are the error S _e 3 of the third sensor 356. Subsequently, in S406, the current value of the operation stroke S _F (final value) is set to zero. Thereafter, in S407, the flag F is set to 1. This completes one execution of this routine.

Thereafter, if the brake pedal 146 is maintained at the operating position and the brake pedal switch 234 is maintained ON, the determination in S401 becomes YES again, and in S403, the detected values S _S 1, S _S 2, S _S 3 are Then, if it is determined in S404 whether or not the flag F is 0, since this time is 1, the determination is NO and the process proceeds to S408.

In S408, it is first determined whether or not the absolute value of the difference between the detection values S _S 1 and S _S 2 is equal to or less than a determination value Δ close to 0. If the determination is YES, the detection value S _S is determined. 1 is selected. If the determination is NO, it is determined whether or not the absolute value of the difference between the detection values S _S 2 and S _S 3 is equal to or less than the determination value Δ. If the determination is YES, the detection value S _S 2 Is selected. If the determination is NO, it is determined whether or not the absolute value of the difference between the detection values S _S 3 and S _S 1 is equal to or less than the determination value Δ. If the determination is YES, the detection value S _S 3 Is selected.

Thereafter, in S409, the current value of the operating stroke S _F is the S _{S *} those selected from the detected value _S S 1 to S _S 3, the error value, i.e., of the error value S _e 1 to S _e 3, Calculation is performed by subtracting the one corresponding to the selected detection value S _{S *} . This completes one execution of this routine.

  Although several embodiments of the present invention have been described in detail with reference to the drawings, various modifications and improvements can be made based on the knowledge of those skilled in the art without departing from the scope of the claims. Of course, the present invention can be implemented in the form of the above.

1 is a system diagram showing a brake system including an electric parking brake device according to a first embodiment of the present invention. It is side surface sectional drawing which shows the electric disc brake in FIG. It is a front view for demonstrating the position where the PKB operating device in FIG. 1 is attached to the vehicle. It is a front view which shows the PKB operating device. It is a side view which shows the PKB operating device. It is a fragmentary sectional front view which expands and shows the principal part of the PKB operating device. 2 is a flowchart showing a brake control routine stored in a ROM of a brake ECU in FIG. It is a flowchart which shows the brake control routine memorize | stored in ROM of brake ECU in the brake system containing the electric parking brake apparatus which is 2nd Embodiment of this invention. It is a systematic diagram which shows the brake system containing the electric parking brake apparatus which is 3rd Embodiment of this invention. FIG. 10 is a flowchart showing a step of calculating a brake pad pressurizing pressure as a brake pad pressurizing calculation routine in a brake control routine stored in a ROM of a brake ECU in FIG. 9. It is a flowchart which shows one modification of the brake pad pressurization calculation routine. It is a flowchart which shows another modification of the said brake pad pressurization calculation routine. It is a flowchart which shows another modification of the said brake pad pressurization pressure calculation routine. It is a systematic diagram which shows the brake system containing the electric parking brake apparatus which is 4th Embodiment of this invention. It is a flowchart which shows the step which calculates brake pad pressurization among brake control routines memorize | stored in ROM of brake ECU in FIG. 14 as a brake pad pressurization calculation routine. It is a graph for demonstrating the content of the brake pad pressurization calculation routine. Of the brake control routine stored in the ROM of the brake ECU in the brake system including the electric parking brake device according to the fifth embodiment of the present invention, the step of calculating the brake pad pressure is shown as the brake pad pressure calculation routine. It is a flowchart. Of the brake control routine stored in the ROM of the brake ECU in the brake system including the electric parking brake device according to the sixth embodiment of the present invention, the step of calculating the brake pad pressure is shown as the brake pad pressure calculation routine. It is a flowchart. It is a time chart for demonstrating the content of the brake pad pressurization calculation routine. It is a flowchart which shows the brake control routine memorize | stored in ROM of brake ECU in the brake system containing the electric parking brake apparatus which is 7th Embodiment of this invention. It is a side view showing a brake pedal and its peripheral components in a brake system including an electric parking brake device according to an eighth embodiment of the present invention. It is a front view which shows the brake pedal and the operation stroke detection apparatus. It is a flowchart which shows the operation stroke detection routine memorize | stored in ROM of brake ECU in the said 8th Embodiment.

Explanation of symbols

14 Ultrasonic motor 16 Electric disc brake 154 PKB operating device 156 PKB release switch 220 Brake ECU
222 Ignition switch 234 Brake pedal switch 236 Operation stroke sensor 300 PKB changeover switch 320 Inclination angle sensor 350 Operation stroke detection device

Claims (6)

(I) a plurality of parking brakes provided on each of the plurality of wheels, (ii) a plurality of electric motors that respectively operate the plurality of parking brakes, and (iii) In the electric parking brake device including a parking brake control device for parking the vehicle by supplying electric power to each of the plurality of electric motors and operating the parking brake corresponding to each electric motor,
An electric parking brake device, wherein the parking brake control device is provided with a combination changing device for changing a combination of the plurality of parking brakes that are operated at substantially the same time.   The combination changing device includes: (a) a combination changing operation member operated by a human to change the combination; and (b) a manual operation corresponding changing means for changing the combination based on the operation of the combination changing operation member. The electric parking brake device according to claim 1.   The combination changing device includes: (c) a vehicle motion state amount sensor that detects a vehicle motion state amount representing a motion state of the vehicle such as a steering angle, a steering angle change speed, and a vehicle speed of the vehicle; and (d) the vehicle motion The electric parking brake device according to claim 1, further comprising an automatic changing unit that changes the combination based on a detection value of a state quantity sensor.   The plurality of wheels are respectively provided on the front, rear, left and right of the vehicle, and the combination includes a first combination including all wheels and a second combination including left and right rear wheels. 4. The electric parking brake device according to any one of 3.   A combination selection in which the combination changing device selects the second combination when the driver may wish to spin-turn the vehicle, and selects the first combination otherwise. The electric parking brake device according to claim 4 including means.   The combination selection means has established at least one of an absolute value of the steering angle of the vehicle exceeding a reference value, an absolute value of the steering angular velocity exceeding a reference value, and a vehicle speed being lower than the reference value. 6. The electric parking brake device according to claim 5, further comprising determination means for determining that the driver may desire to spin-turn the vehicle.

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