JP5100803B2 - Brake device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular brake device having an electrical operation type parking brake driving means capable of actuating the electrical-operation-type parking brake driving means without requiring any driver's troublesome operation, reducing the actuation frequency, and enhancing the durability along with the suppression of noise emission. <P>SOLUTION: The vehicular brake device includes brake hydraulic pressure sensors 15A, 15B for detecting the brake hydraulic pressure to be output from a hydraulic pressure generating means M to hydraulic-operation type wheel brakes 2B, 2D corresponding to the braking operation. A controller C starts the conduction of electrical-operation-type parking brake driving means 24A, 24B according to the excess of the brake hydraulic pressure to be detected by the brake hydraulic pressure sensors 15A, 15B over the reference value in a stopped state of a vehicle, and controls the conduction of the electrical-operation-type parking brake driving means so that the time rate of change of the operational quantity of the electrical-operation-type parking brake driving means 24A, 24B when the conduction is started is smaller than that of the operational quantity when the operational quantity reaches the target value. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a hydraulic pressure generating means for outputting a hydraulic pressure corresponding to a brake operation of a vehicle driver, and a hydraulically operated type mounted on a wheel so as to operate based on the output hydraulic pressure of the hydraulic pressure generating means. A wheel brake, an electrically operated parking brake driving means for activating the wheel brake or a parking brake mounted on a wheel separately from the wheel brake in response to energization, and the electrically operated parking brake The present invention relates to a vehicle brake device including a controller that controls energization of a driving unit.

  When the vehicle shift position is set to the parking position, when the vehicle is stopped on a slope, or when the driver manually operates the operation switch, the electrically operated parking brake driving means is activated to enter the parking brake state. A vehicular brake device that can be switched is already known, for example, from US Pat.

Japanese Patent No. 3595249

  By the way, when the electrically operated parking brake driving means is operated, noise is generated along with the operation and electric power is consumed. As described above, the electrically operated parking brake driving means is operated when stopping on a slope. Depending on the setting of the judgment value for judging a slope, the frequency of operation increases, the frequency of noise generation increases, the power consumption increases, and the durability of the electrically operated parking brake drive means also decreases. To do. Further, the operation of the shift position to the parking position and the manual operation of the operation switch require a driver's operation and are troublesome.

  The present invention has been made in view of such circumstances, and eliminates the troublesome operation of the driver to operate the electrically operated parking brake drive means, while reducing the operation frequency and generating noise accompanying the operation. An object of the present invention is to provide a vehicular brake device that suppresses the above and contributes to improvement in durability.

In order to achieve the above object, a first aspect of the present invention provides a hydraulic pressure generating means for outputting a brake hydraulic pressure corresponding to a brake operation of a vehicle driver, and a hydraulic pressure control circuit connected to the hydraulic pressure generating means. the wheel brakes hydraulically actuated to operate based on the output hydraulic pressure of the connected liquid pressure generating means, electrically operated parking brake drive having an electric motor for generating the energizing the actuation force allowed to operate the parking brake of the vehicle And a controller for controlling the energization of the electrically operated parking brake drive means and the operation of the hydraulic pressure control circuit, and the electrically operated parking brake drive means is configured to supply the electric motor when energized to the electric motor. the vehicle brake system braking force can be output to the wheel brake corresponding to the amount of operation, the fluid from the fluid pressure generating means in response to the driver's brake operation A brake fluid pressure sensor for detecting a brake fluid pressure output to an actuated wheel brake, wherein the controller detects whether the brake fluid pressure detected by the brake fluid pressure sensor exceeds a reference value when the vehicle is stopped; in response to start the power supply to the electric motor, it controls the energization of the electric-operated parking brake drive means, until the operation amount of the electric motor becomes the target operation amount from the energization start When the brake hydraulic pressure of the hydraulically operated wheel brake decreases beyond a predetermined value, the hydraulic pressure control circuit is controlled to maintain the brake hydraulic pressure, and the brake hydraulic pressure is The time change rate of the operation amount of the electric motor when energization to the electric motor is started in response to exceeding the reference value in a vehicle stop state is when the operation amount reaches the target operation amount. And wherein the less than the time rate of change of the operation amount.

According to a second aspect of the invention, in addition to the configuration of the first aspect of the invention, the target operation amount is an operation amount that provides a braking force capable of maintaining the vehicle in a stopped state, and corresponds to the reference value. it characterized in that it is set to a low predetermined operation amount than the operation amount.

According to the first aspect of the present invention, the operation of the electrically operated parking brake driving means, that is, the electric operation is performed on the condition that the vehicle is in a stopped state and the brake force by the hydraulic pressure exceeds the predetermined brake force. Since the motor is energized and the braking force is obtained by the hydraulic pressure, the operation is switched to obtain the parking brake state by the operation of the electrically operated parking brake driving means by energizing, so that the driver's troublesome operation is unnecessary. While operating the electrically operated parking brake driving means, the operating frequency can be reduced, and the durability can be enhanced while suppressing the generation of noise accompanying the operation.

Further, if the brake fluid pressure of the hydraulically operated wheel brake decreases beyond a predetermined value during the period from the start of energization to the target actuation amount, the brake fluid pressure is maintained. Therefore, it is avoided that the brake force due to the brake fluid pressure is reduced until the motor operation amount of the electrically operated parking brake driving means reaches the target operation amount, and the vehicle is activated by the operation of the electrically operated parking brake drive means. It is possible to reliably prevent undesired vehicle movement unintended by the driver before maintaining the stop state.

According to the second aspect of the invention, Ru can maintain the stopped state of the vehicle by electrically operated parking brake drive unit.

The figure which shows the whole structure of the drive system and brake system of a vehicle Diagram showing the configuration of the hydraulic control circuit Longitudinal sectional view of a disc brake with electric actuated parking brake drive means Block diagram showing the configuration of the brake control system The figure which shows the setting map of the hydraulic pressure equivalent value of the reference value which judges energization start, and the target operation amount of an electrically operated parking brake drive means The figure which shows the change of the brake fluid pressure at the time of a vehicle stop, and the operating force of an electrically operated parking brake drive means Diagram corresponding to Fig. 6 when the brake operating force is released halfway when the vehicle is stopped The figure corresponding to FIG. 6 and FIG. 7 when the electrically operated parking brake drive means fails

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below based on one embodiment of the present invention shown in the accompanying drawings.

  1 to 8 show an embodiment of the present invention, FIG. 1 is a diagram showing the overall configuration of a drive system and a brake system of a vehicle, FIG. 2 is a diagram showing the configuration of a hydraulic pressure control circuit, and FIG. Is a longitudinal sectional view of a disc brake provided with an electrically operated parking brake driving means, FIG. 4 is a block diagram showing a configuration of a brake control system, and FIG. 5 is a reference value for determining the start of energization and electrically operated parking brake driving means. FIG. 6 is a diagram showing a setting map of the hydraulic pressure equivalent value of the target actuation amount, FIG. 6 is a diagram showing changes in brake fluid pressure when the vehicle is stopped and the actuation force of the electrically operated parking brake driving means, and FIG. FIG. 8 is a view corresponding to FIG. 6 when the operating force is released halfway, and FIG. 8 is a view corresponding to FIGS. 6 and 7 when the electrically operated parking brake drive means is out of order.

  First, in FIG. 1, the output from the automatic transmission T connected in series to the engine E is transmitted to the left front wheel WA and the right front wheel WC which are drive wheels of the vehicle V of the front engine / front drive (FF). These front wheels WA and WC are equipped with a left front wheel brake 2A and a right front wheel brake 2C, which are disc brakes. Further, a right rear wheel wheel brake 2B and a left rear wheel wheel brake 2D, which are disc brakes, are mounted on the right front wheel WB and the left rear wheel WD, which are driven wheels.

  A master cylinder M as a hydraulic pressure generating means for outputting a brake hydraulic pressure in response to the operation of the brake pedal P by the vehicle driver is a tandem type, and the master cylinder M is connected via a hydraulic pressure control circuit 5. It is connected to each wheel brake 2A-2D.

  In FIG. 2, the tandem master cylinder M includes first and second output ports 1A and 1B that output hydraulic pressure in response to the driver operating the brake pedal P, and the first and second outputs. The ports 1A and 1B are connected to the wheel brakes 2A to 2D via the hydraulic pressure control circuit 5.

  The hydraulic pressure control circuit 5 includes a first hydraulic pressure path 20A that can communicate with the first output port 1A, a second hydraulic pressure path 20B that can communicate with the second output port 1B, and first and second output ports 1A and 1B. Also, the first and second pressure regulating valves 17A and 17B interposed between the first and second hydraulic pressure paths 20A and 20B, and the wheel brake side hydraulic pressure path 4A and the first liquid connected to the left front wheel brake 2A, respectively. A normally-open electromagnetic valve 6A interposed between the pressure passages 20A, and a normally-open electromagnetic valve interposed between the wheel brake side hydraulic pressure passage 4B and the first hydraulic pressure passage 20A connected to the right rear wheel brake 2B. A valve 6B, a normally open solenoid valve 6C interposed between the wheel brake side hydraulic pressure path 4C and the second hydraulic pressure path 20B connected to the right front wheel wheel brake 2C, and a wheel connected to the left rear wheel wheel brake 2D Brake side hydraulic path 4D and second hydraulic path 20 A normally open solenoid valve 6D interposed therebetween, check valves 7A to 7D connected in parallel to the normally open solenoid valves 6A to 6D, and the first and second output ports 1A and 1B individually. Corresponding first and second reservoirs 8A and 8B, normally closed electromagnetic valves 9A and 9B interposed between the first reservoir 8A and the wheel brake side hydraulic pressure passages 4A and 4B, the second reservoir 8B and the wheel brake The normally closed solenoid valves 9C, 9D interposed between the side hydraulic pressure paths 4C, 4D and the common electric motor 11 are driven, and the discharge side is connected to the first and second hydraulic pressure paths 20A, 20B. The first and second pumps 10A and 10B, the first and second reservoirs 8A and 8B, and the one-way valves 19A and 19B interposed between the suction sides of the first and second pumps 10A and 10B; 2nd output port 1A, 1B First and second suction valves 18A, 18B interposed between the suction sides of the first and second pumps 10A, 10B, the first and second hydraulic pressure paths 20A, 20B, and the first and second pumps 10A. First and second dampers 13A and 13B connected between the discharge sides of 10B.

  The wheel brake side hydraulic pressure passages 4A and 4C include brake fluid pressure acting on the left front wheel brake 2A and the right front wheel brake 2C, that is, pressure regulating valves 17A and 17B and normally open solenoid valves 6A and 6C. In a normal service brake state in which the valve is opened, brake hydraulic pressure sensors 15A and 15B for detecting the hydraulic pressures of the first and second hydraulic pressure paths 20A and 20B are provided.

  The pressure regulating valves 17A and 17B are normally open linear solenoid valves that can switch between communication and blocking between the first and second output ports 1A and 1B and the first and second hydraulic pressure sources 20A and 20B. It is also possible to operate so as to regulate the hydraulic pressure in the first and second hydraulic pressure paths 20A and 20B.

  Thus, by operating the electric motor 11 with the first and second suction valves 18A and 18B excited and opened, the first and second pumps 10A and 10B are sucked from the master cylinder M side and added. The pressed brake fluid is discharged to the first and second hydraulic pressure paths 20A and 20B. At this time, the hydraulic pressures of the first and second hydraulic pressure paths 20A and 20B are kept constant by controlling the operation of the pressure regulating valves 17A and 17B according to the brake hydraulic pressure detected by the brake hydraulic pressure sensors 15A and 15B. can do.

  That is, the first and second pumps 10A, 10B and the first and second pressure regulating valves 17A, 17B apply a certain hydraulic pressure to the first and second hydraulic pressure paths 20A, 20B during non-braking operation. By controlling the constant hydraulic pressure in the first and second hydraulic pressure paths 20A and 20B by the normally open solenoid valves 6A to 6D and the normally closed solenoid valves 9A to 9D, the wheel brakes 2A to 2D are mutually controlled. Different brake fluid pressures can be applied, whereby automatic brake control such as behavior stability control and traction control during vehicle travel can be executed.

  At the time of service braking, the first and second pressure regulating valves 17A and 17B are opened and the first and second suction valves 18A and 18B are closed. The normally open solenoid valves 6A to 6D and By executing the anti-lock brake control for controlling the opening / closing operation of the normally-open and normally-closed solenoid valves corresponding to the wheels that are likely to be locked during service brake among the closed-type solenoid valves 9A to 9D, It is possible to brake efficiently without locking the wheels.

  In FIG. 3, a right rear wheel wheel brake 2 </ b> B that is a disk brake mounted on the right rear wheel WB is provided on a disk rotor 25 that rotates together with a wheel of a wheel (not shown), a caliper body 26, and both side surfaces of the disk rotor 25. A pair of left and right friction pads 27, 28 disposed between the disk rotor 25 and the caliper body 26 so as to face each other are provided.

  The caliper body 26 is formed in a bottomed cylindrical shape having an axis parallel to the axis of the disk rotor 25, and is slidably supported in a direction along the axis of the disk rotor 25 by a support portion on the vehicle body side (not shown). A body main portion 26a and an arm portion 26b extending from the body main portion 26a to the opposite side across the disk rotor 25, and a friction pad facing one side of the disk rotor 25 on the body main portion 26a side Reference numeral 27 denotes a lining 31 that is slidably contacted with the disk rotor 25 so as to exert a frictional force. The lining 31 is provided on the back metal 29. A lining 32 that can exert a frictional force is provided on the back metal 30.

  In the body main portion 26 a of the caliper body 26, an annular step 35 is formed between the cylinder hole 33 having one end opened to the friction pad 27 side and the other end of the cylinder hole 33. A through hole 34 having a small diameter is provided coaxially with an axis parallel to the disk rotor 25.

  The cylinder hole 33 is formed with a bottomed cylindrical brake piston 37 that forms a hydraulic chamber 36 between the stepped portion 35 and closes the front end. The front end of the brake hole 37 contacts the back metal 29 of the one friction pad 27. An annular piston seal 38 interposed between the caliper body 26 and the brake piston 37 is attached to the inner surface of the cylinder hole 33 so as to be slidable in the axial direction. An annular dust boot 39 is provided between the brake piston 37 and the body main portion 26a is provided with an input port 40 leading to the hydraulic pressure chamber 36. The wheel brake side hydraulic pressure path 4B is connected to the input port 40. Is done.

  Thus, as the hydraulic pressure acts on the hydraulic pressure chamber 36 from the wheel brake side hydraulic pressure path 4B via the input port 40, the brake piston 37 advances, and accordingly, the disc rotor 25, that is, the right rear wheel WB is moved forward. Brake force will act.

  By the way, the right rear wheel wheel brake 2B is provided with an electrically operated parking brake driving means 24A capable of exerting an operating force for operating the wheel brake 2B in response to energization. 24A is configured such that the output of the electric motor 41 is transmitted to the brake piston 37 via the speed reduction mechanism 42 and the screw mechanism 43.

  The screw mechanism 43 is accommodated in the body main portion 26a of the caliper body 26, and the speed reduction mechanism 42 and the electric motor 41 are accommodated in a housing 44 having a flange 44a coupled to a flange 26c provided in the body main portion 26a. The

  The screw mechanism 43 is opposite to the brake piston 37, a screw shaft 45 that is coaxial with the cylinder hole 33, a nut 46 that is engaged with the brake piston 37 and cannot be relatively rotated, and is screwed into the screw shaft 45. And a spindle 47 provided coaxially and integrally with the rear end of the screw shaft 45 on the side.

  The screw shaft 45 is screwed into a cylindrical nut 46 surrounding the screw shaft 45 in the brake piston 37, and the front end of the nut 46 is in contact with the inner surface of the front end of the brake piston 37. Further, a plurality of engaging protrusions 46a projecting laterally from the front end portion of the nut 46 are engaged with a plurality of locking portions 37a provided on the inner surface near the front end of the brake piston 37. The rotation is made impossible and the brake piston 37 is engaged.

  The spindle 47 passes through the through-hole 34 of the body main portion 6a in a rotatable manner, and an O-ring 48 is interposed between the spindle 47 and the body main portion 6a. In addition, a flange portion 49 that projects outward in the radial direction is provided integrally with the connecting portion of the spindle 47 and the screw shaft 45, and an annular shape formed at the center portion of the flange portion 49 and the step portion 35. A thrust bearing 50 is interposed between the receiving seat 35a.

  The reduction mechanism 42 is a two-stage planetary gear type interposed between the electric motor 41 and the spindle 47, and the electric motor 41 and the reduction mechanism 42 are arranged coaxially with the spindle 47. Thus, the speed reduction mechanism 42 is rotatably supported by the input side sun gear 53 that is coaxially connected to the electric motor 41 and the input side planetary gear carrier 54 that is fixed to the housing 44, and meshes with the input side sun gear 53. A plurality of input-side planetary gears 55; an input-side internal gear 56 that meshes with the input-side planetary gears 55; an output-side sun gear 57 that rotates integrally with the input-side sun gear 53; A plurality of output planetary gears 59 that are rotatably supported by an output planetary gear carrier 58 that is coaxially engaged with the output 47 and meshes with the output sun gear 57, and meshed with the output planetary gears 59. An output-side internal gear 60 that rotates integrally with the input-side internal gear 56 is provided.

  The input side and output side internal gears 56, 60 are coaxially and integrally coupled, and are rotatably supported by the housing 44. The input-side sun gear 53 and the output-side sun gear 57 are provided on a rotating shaft 52 that is coaxially connected to the electric motor 41, and the other end of the rotating shaft 52 is an output member of the speed reduction mechanism 42. Is inserted into a recess 61 provided in the output-side planetary gear carrier 58, and a ball bearing 62 is interposed between the inner periphery of the recess 61 and the rotary shaft 52. Further, a support hole 63 coaxial with the spindle 47 is provided in an end wall of the housing 44 on the body main portion 6a side, and is provided integrally with the output-side planetary gear carrier 58 on the side opposite to the concave portion 61 to support the support. A ball bearing 65 is interposed between the connecting shaft portion 64 inserted coaxially into the hole 63 and the housing 44.

  In such a two-stage planetary gear type reduction mechanism 42, the number of teeth of the input side sun gear 53 is ZA, the number of teeth of the input side planetary gear 55 is ZB, the number of teeth of the input side internal gear 56 is ZC, and the output side sun gear. When the number of teeth of 57 is ZD, the number of teeth of the output-side planetary gear 59 is ZE, and the number of teeth of the output-side internal gear 60 is ZF, the reduction ratio U is obtained by the following equation.

U = {ZA · ZF−ZD · ZC} / {ZC · (ZD + ZF)}
A non-circular locking recess 66 is provided on the rear end surface of the spindle 47 provided in the screw mechanism 43, and an engagement is provided at the front end of the connecting shaft portion 64 provided in the output-side planetary gear carrier 58 of the speed reduction mechanism 42. In this state, an engaging protrusion 67 that integrally engages with the locking recess 66 is provided so as to disable relative rotation of the spindle 47 and the output planetary gear carrier 58.

  Thus, the output of the electric motor 41 is decelerated by the speed reduction mechanism 42 and transmitted to the spindle 47, whereby the screw shaft 45 of the screw mechanism 43 rotates and the brake piston 37 and the nut 46 are prevented from rotating. The disk rotor 25 is clamped from both sides by the friction pads 27 and 28 due to the action and reaction caused by the sliding of the piston 37 in the axial direction, whereby a braking force is obtained.

  The electric motor 41 is additionally provided with an operation amount detector 68A for detecting the operation amount of the electric motor 41, that is, the operation amount of the electrically operated parking brake drive means 24A.

  By the way, the screw mechanism 43 is non-self-locking by enabling the friction pads 27 and 28 to be moved backward from the disk rotor 25 by a reaction force from the disk rotor 25 side in a disconnected state with the speed reduction mechanism 42. Configured to mold. On the other hand, the speed reduction mechanism 42 is configured to be a self-locking type so as to maintain the operating state of the screw mechanism 43 even when the electric motor 41 is not energized when connected to the screw mechanism 43. That is, the electrically actuated parking brake driving means 24A can exhibit the operating force that operates the right rear wheel wheel brake 2B in response to energization and can maintain the operating state even when the energization is released in the operating state.

  The left rear wheel wheel brake 2D is configured in the same manner as the right rear wheel wheel brake 2B described above, and is electrically operated parking brake driving means 24B configured in the same manner as the electrically operated parking brake driving means 24A (see FIG. 1) is attached to the left rear wheel wheel brake 2D, and an electrically operated parking brake drive means 24B includes an operation amount detector 68B (see FIG. 1) for detecting the operation amount of the electrically operated parking brake drive means 24B. ) Is attached.

  In FIG. 4, the controller C, which is fed from the battery 71 and controls the operation of the hydraulic control circuit 5 and the electrically operated parking brake drive means 24A, 24B, has automatic operation of the electrically operated parking brake drive means 24A, 24B. Automatic operation permission switch 72 for switching between permission and non-permission, manual operation instruction switch 73 for manually instructing brake operation and release of electrically operated parking brake drive means 24A, 24B, left front wheel WA, right rear wheel WB, right Wheel speed sensors SA, SB, SC, SD for detecting the wheel speeds of the front wheel WC and the left rear wheel WD, and shift position determination means 74 for determining whether or not the shift position of the automatic transmission T is a parking position; , Brake fluid pressure sensors 15A and 15B for detecting the brake fluid pressure of the service brake, and electrically operated parking brake Signals are input from the operation amount detectors 68A and 68B for detecting the operation amounts of the moving means 24A and 24B, and based on these signals, the controller C operates the hydraulic control circuit 5 and the electrically operated parking brake. It controls the operation of the driving means 24A, 24B and the operation of the operation lamp 75 and the alarm lamp 76 for displaying the operating state of the electrically operated parking brake driving means 24A, 24B to the vehicle driver.

  The manual operation instruction switch 73 is a self-returning three-position changeover switch, and is always in the neutral position when the hand is released, while the manual operation instruction switch 73 is operated to either the activation or release side. Only an operation instruction signal or a release instruction signal is output. The automatic operation permission switch 72 is a two-position changeover switch and selects either one of the automatic operation permission position and the non-permission position.

  Here, parking control by the controller C in a state where automatic operation is permitted by the automatic operation permission switch 72 will be described. When the vehicle driver depresses the brake pedal P, detection of each wheel speed sensor SA to SD is performed. Brake fluid pressure that detects a brake fluid pressure that is a physical quantity related to the brake force exerted by the right rear wheel brake 2B and the left rear wheel brake 2D in a state where it can be determined that the vehicle has stopped based on the value When the detection values of the sensors 15A and 15B exceed the reference value, the controller C starts energization of the electrically operated parking brake driving means 24A and 24B and activates the electrically operated parking brake driving means 24A and 24B. The vehicle driver is notified that the electrically operated parking brake drive means 24A and 24B are operating. Blink the operating lamp 75 in order.

  Here, the reference value is set larger than the physical quantity corresponding to the braking force required to maintain the vehicle in a stopped state, that is, the brake fluid pressure. Thus, the brake hydraulic pressure required to maintain the vehicle in a stopped state changes according to the road surface gradient as shown by the chain line in FIG. 5. In this embodiment, the vehicle has a road surface gradient of 30%. The reference value is set to be larger than the brake fluid pressure at which can be maintained in a stopped state.

  In addition, when the shift position determination means 74 determines that the shift position of the automatic transmission T is the parking position, the controller C is based on the reference value set to a larger value compared to the non-parking position. In this embodiment, the reference value for the non-parking position is, for example, 5 MPa as shown by the first straight line L1 in FIG. On the other hand, the reference value at the parking position is, for example, 6 MPa as shown by the second straight line L2 in FIG.

  In addition, the controller C controls the energization operation of the electrically operated parking brake drive means 24A, 24B by determining a target operation amount so as to obtain a braking force required to maintain the vehicle stop state. The controller C controls the energization operation of the electrically operated parking brake drive means 24A and 24B so that the operation amount detected by the amount detectors 68A and 68B reaches the target operation amount, and the electrically operated parking brake drive means 24A and 24B. When the operation amount reaches the target operation amount, the operation of the electrically operated parking brake driving means 24A, 24B is stopped and the operation lamp 75 is turned off.

  Here, the target operation amount of the electrically operated parking brake drive means 24A, 24B acts on the left front wheel brake 2A, the right front wheel brake 2C, the right rear wheel brake 2B, and the left rear wheel brake 2D. The brake force corresponding to the brake force obtained by the entire vehicle when the brake fluid pressure is the third straight line L3 in FIG. 5 is used for the right rear wheel accompanying the operation of the electrically operated parking brake drive means 24A, 24B. It is set so as to be obtained by the operation of the wheel brake 2B and the left rear wheel brake 2D, and the third straight line L3 is, for example, 4 MPa.

  Further, the controller C determines that the brake fluid pressure detected by the brake fluid pressure sensors 15A and 15B is applied to the brake operation until the operation amount of the electrically operated parking brake drive means 24A and 24B reaches the target operation amount from the start of the operation. When the pressure decreases beyond a predetermined value (for example, 0.5 MPa) that can be determined as the release of force, the hydraulic pressure acting on the four-wheel brakes 2A to 2D is maintained (FIG. 7 described later). And the time t2 in FIG. 8), between the left front wheel brake 2A and the right rear wheel brake 2B and the master cylinder M, as well as the right front wheel brake 2C and the left rear wheel brake 2D, and the master cylinder. The pressure regulating valves 17A and 17B, which are normally open solenoid valves respectively interposed between them, are controlled to be closed.

  Further, the controller C ends the valve closing control of the pressure regulating valves 17A and 17B when the operation amount of the electrically operated parking brake driving means 24A and 24B reaches the target operation amount.

  Further, the controller C determines that a failure has occurred when the operation amount of the electrically operated parking brake drive means 24A, 24B does not reach the target operation amount even after a predetermined time (for example, 3 seconds) has elapsed from the start of the operation, and performs failure processing. In the failure processing, the energization of the electrically operated parking brake drive means 24A, 24B is stopped and the alarm lamp 76 is turned on, and the hydraulic pressure is maintained by the valve closing control of the pressure regulating valves 17A, 17B. If there is, the pressure regulating valves 17A and 17B are opened.

  Next, the operation of this embodiment will be described. The brake hydraulic pressure which is a physical quantity related to the braking force exerted by the right rear wheel brake 2B and the left rear wheel brake 2D based on the output hydraulic pressure of the master cylinder M. The controller C starts energization of the electrically operated parking brake drive means 24A, 24B when the detected values of the brake hydraulic pressure sensors 15A, 15B exceed the reference value when the vehicle is stopped. For example, in the state where the shift position of the automatic transmission T is in the non-parking position, as shown in FIG. 6, the operation of the electrically operated parking brake driving means 24A, 24B is performed at time t1 when the brake fluid pressure exceeds 5 MPa, for example. Be started.

  Thus, the operation of the electrically operated parking brake drive means 24A, 24B is started on the condition that the vehicle is in a stopped state and the brake force by the hydraulic pressure exceeds the predetermined brake force. Therefore, the operation of the electrically operated parking brake driving means 24A, 24B by energization is switched from the state where the braking force is obtained by the operation of the electrically operated parking brake driving means 24, so that the driver's troublesome operation is unnecessary and the electrically operated parking brake driving means is unnecessary. It is possible to increase the durability while operating the 24A and 24B, reducing the frequency of the operation, and suppressing the generation of noise accompanying the operation.

  Moreover, since the reference value for determining the start of energization of the electrically operated parking brake drive means 24A, 24B is set larger than the brake fluid pressure corresponding to the brake force required to maintain the vehicle in a stopped state. The operation frequency of the electrically operated parking brake drive means 24A, 24B can be reduced by confirming the intention of the vehicle driver to stop the vehicle and operating the electrically operated parking brake drive means 24A, 24B.

  In addition, the controller C controls the energization operation of the electrically operated parking brake drive means 24A and 24B by determining a target operation amount so as to obtain the braking force required to maintain the vehicle stop state. At time 1t3 when the operating amount of the electrically operated parking brake driving means 24A, 24B reaches the target operating amount after a time T1 (for example, 1 second) has elapsed from t1, the electrically operated parking brake driving means 24A, 24B are energized. I try to stop. Therefore, the stop state of the vehicle can be reliably maintained by the electrically operated parking brake driving means 24A, 24B.

Thus, the controller C starts energization of the electrically operated parking brake driving means 24A and 24B in response to the brake fluid pressure detected by the brake fluid pressure sensors 15A and 15B exceeding the reference value when the vehicle is stopped. However, in the present invention, as shown in FIG. 6, the time change rate of the operation amount of the electrically operated parking brake driving means 24A, 24B at the start of energization is the electrically operated parking brake driving means 24A. , and Tsu of smaller than the operating amount of the time rate of change of when the operation amount of 24B reaches the target operation amount.

  Further, when the shift position determination means 74 determines that the shift position of the automatic transmission T is the parking position, the controller C is based on a reference value that is set to a larger value compared to the non-parking position. This determines the start of energization of the electrically operated parking brake drive means 24A, 24B, and can thereby avoid unnecessary operation of the electrically operated parking brake drive means 24A, 24B in the non-parking state. .

  Further, as shown in FIG. 7, the controller C starts the operation at time t1, and after the operation amount of the electrically operated parking brake drive means 24A, 24B reaches the target operation amount, the brake fluid pressure sensor 15A. , 15B, the left front wheel brake 2A and the right rear at time t2 when the hydraulic pressure is decreased beyond a predetermined value (for example, 0.5 MPa) that can be determined to be the release of the brake operation force. The pressure regulating valves 17A and 17B provided between the wheel brake 2B and the master cylinder M, and between the right front wheel brake 2C and the left rear wheel brake 2D and the master cylinder M are closed. Since the control is performed, the brake force due to the hydraulic pressure is reduced until the operation amount of the electrically operated parking brake driving means 24A, 24B reaches the target operation amount. And avoid, electrically operated parking brake drive means 24A, that is not intended undesired vehicle movement of the driver occurs prior to maintain the stopped state of the vehicle by the operation of 24B can be reliably prevented.

  Moreover, since the controller C ends the valve closing control of the pressure regulating valves 17A and 17B at the time t3 when the operation amount of the electrically operated parking brake drive means 24A and 24B reaches the target operation amount, the electrically operated parking brake drive means After confirming that a sufficient braking force is obtained by the operation of 24A and 24B, the control of the pressure regulating valves 17A and 17B can be terminated so as to release the braking force due to the hydraulic pressure.

  Further, the controller C determines that a failure occurs when the operation amount of the electrically operated parking brake driving means 24A, 24B does not reach the target operation amount even after a predetermined time T2, for example, 3 seconds has elapsed from the start of the operation, and executes failure processing. As shown in FIG. 8, after starting the operation at time t1 and controlling the pressure regulating valves 17A and 17B to close at time t2, at time t4 when time T2 has elapsed from time t1, the controller C Then, the energization of the electrically operated parking brake driving means 24A, 24B is stopped, the alarm lamp 76 is turned on, and the pressure regulating valves 17A, 17B are opened.

  Thus, if the operation amount of the electrically operated parking brake driving means 24A, 24B does not reach the target operation amount even after the predetermined time T2 has elapsed from the start of the operation, it can be determined that there is a failure. Failure processing can be executed.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. It is.

  For example, in the above-described embodiment, the case where the electrically operated parking brake driving means 24A, 24B are attached to the hydraulically operated right rear wheel brake 2B and the left rear wheel brake 2D has been described. The present invention can also be applied to a parking brake that is different from the pressure-actuated wheel brake and is driven by an electrically operated parking brake driving means.

2B, 2D ... Wheel brake (hydraulic wheel brake, parking brake)
5 ..., Hydraulic pressure control circuits 15A and 15B... Brake hydraulic pressure sensors 17A and 17B ... pressure regulating valves 24A and 24B which are normally open solenoid valves. Brake drive means
41 ... Electric motor C ... Controller M ... Master cylinder (hydraulic pressure generating means)

Claims (2)

A hydraulic pressure generating means (M) for outputting a brake hydraulic pressure corresponding to the brake operation of the vehicle driver, and connected to the hydraulic pressure generating means (M) via a hydraulic pressure control circuit (5) to generate the hydraulic pressure An electric motor (41 ) that generates a hydraulically operated wheel brake (2B, 2D) that operates based on the output hydraulic pressure of the means (M) and an operating force that operates the parking brake (2B, 2D) of the vehicle. ) Having electrically operated parking brake driving means (24A, 24B) and a controller (C) for controlling energization of the electrically operated parking brake driving means (24A, 24B) and operation of the hydraulic pressure control circuit (5 ). It equipped with a door,
The electrically operated parking brake drive means (24A, 24B) outputs a braking force corresponding to the operation amount of the electric motor (41) to the wheel brakes (2B, 2D) when the electric motor (41) is energized. In a vehicle brake device that is possible ,
Brake hydraulic pressure sensors (15A, 15B) for detecting brake hydraulic pressure output from the hydraulic pressure generating means (M) to the hydraulically operated wheel brakes (2B, 2D) in response to a driver's brake operation Including
Wherein the controller (C) starts energization of the the electric motor (41) in response to the brake fluid pressure detected by the brake fluid pressure sensor (15A, 15B) exceeds the reference value in the stop state of the vehicle As described above, the energization of the electrically actuated parking brake drive means (24A, 24B) is controlled, and the hydraulic pressure is reduced from when the operation amount of the electric motor (41) reaches the target operation amount. When the brake fluid pressure of the actuating wheel brake (2B, 2D) decreases beyond a predetermined value, the fluid pressure control circuit (5) is controlled so as to maintain the brake fluid pressure,
The rate of change over time of the operation amount of the electric motor (41) when energization of the electric motor (41) is started in response to the brake fluid pressure exceeding a reference value in a stopped state of the vehicle is the operation rate thereof. A vehicular brake device characterized in that the amount is smaller than the time change rate of the operation amount when the amount reaches the target operation amount . The target operation amount is an operation amount that provides a braking force capable of maintaining the vehicle in a stopped state, and is set to a predetermined operation amount that is lower than an operation amount corresponding to the reference value. 1 a vehicle brake equipment according.

Images