JP4528797B2 - Brake device - Google Patents

Description

  The present invention relates to a brake device capable of adjusting an initial position of a brake pedal.

  In recent years, a motor cylinder for applying hydraulic pressure to a braking force generator provided on a wheel based on pedal operation information such as a pedaling force and a stroke of a brake pedal (hereinafter also simply referred to as a pedal) input to an ECU of a vehicle, A brake device that drives and controls a hydraulic pump has been proposed.

  This type of electrical signal braking control system, so-called brake-by-wire, is more faithful to pedal operation than a hydraulic control system in which a pedal and a master cylinder are directly connected. And smooth braking can be realized.

  Patent Document 1 discloses a brake device that generates a pedal reaction force with an electric actuator based on pedal operation information and generates a braking force based on a command from an ECU. In this case, the initial position of the pedal can be changed by driving the electric actuator.

JP 2006-281802 A

  Incidentally, in this type of brake device, there is a demand for further reduction in the capacity of the electric actuator connected to the pedal in order to reduce the power consumption of the vehicle battery and to make the installation space compact.

  The present invention has been made in relation to the above-described conventional technology, and can achieve an optimal pedal reaction force while reducing the capacity of the electric actuator provided in the brake pedal, and a reliable brake pedal position. It is an object of the present invention to provide a brake device that can be adjusted.

  A brake device according to the present invention is connected to a brake pedal and generates a hydraulic pressure by operating the brake pedal, a hydraulic pressure generating unit that generates hydraulic pressure based on operation information of the brake pedal, and the master A braking force generating unit that generates a brake braking force by a hydraulic pressure generated by the cylinder or the hydraulic pressure generating unit and a master cylinder that communicates with the braking force generating unit, and a reaction force is generated by the brake pedal by the hydraulic pressure generated by the master cylinder A pedal simulator, a fail-safe valve for communicating or blocking a main path between the master cylinder and the braking force generator, and a simulator valve for communicating or blocking a path between the main path and the pedal simulator; Brake device comprising a brake valve for communicating or blocking a path between the main path and the hydraulic pressure generating unit An actuator connected to the brake pedal for adjusting the position of the brake pedal, and an auxiliary path for communicating the braking force generator with a hydraulic pressure adjusting reservoir tank. When adjusting the position, the fail-safe valve and the brake valve are in communication and the simulator valve is shut off.

  According to such a configuration, the hydraulic pressure of the master cylinder generated when the brake pedal is initially adjusted by the actuator can be released to the reservoir tank via the auxiliary path. That is, the hydraulic pressure in the system adjusted by the reservoir tank at the time of adjusting the initial position of the brake pedal is maintained even after the completion of the initial position adjustment. For this reason, the output of the actuator for maintaining the initial position after adjustment of the brake pedal can be reduced, and the capacity of the actuator can be reduced. In addition, since the reaction force at the time of pedal operation can be applied by the pedal simulator, it is not necessary for the actuator to generate the reaction force, and the actuator can be further reduced in capacity.

  Furthermore, in the brake device according to the present invention, by providing the master cylinder in addition to the fluid pressure generating unit, for example, the braking force is obtained by the fluid pressure of the master cylinder even when the system is off such as ignition off. Can do.

  In addition, when the hydraulic pressure generating unit communicates with the braking force generating unit via the brake valve and the auxiliary path communicates between the hydraulic pressure generating unit and the reservoir tank, It is preferable because the hydraulic pressure (fluid amount) in the pressure generating unit can be adjusted from the reservoir tank via the auxiliary path.

  According to the present invention, the hydraulic pressure of the master cylinder generated when the brake pedal is initially adjusted by the actuator can be released to the reservoir tank via the auxiliary path. Accordingly, the reaction force to the brake pedal during the initial position adjustment can be reduced, and the hydraulic pressure in the hydraulic system after the initial adjustment of the brake pedal can be maintained. Can be realized. Furthermore, since the reaction force at the time of pedal operation can be generated by the pedal simulator, the actuator hardly needs to generate the reaction force, and the actuator can be further reduced in capacity.

  In addition, according to the present invention, the master cylinder is provided in addition to the hydraulic pressure generator that is driven based on the operation information of the brake pedal. For this reason, for example, even when the system is off, such as when the ignition is off, it is possible to generate a braking force by the hydraulic pressure from the master cylinder that is linked to the pedal operation.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a brake device according to the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a block circuit diagram of a brake device 10 according to an embodiment of the present invention. The brake device 10 according to the present embodiment is mounted on a vehicle such as an automobile, and a braking force generator (provided on the left wheel LW and the right wheel RW) based on the operation of a pedal (brake pedal) 12 by a driver (operator) ( Calipers, wheel cylinders, brake cylinders) 14L, 14R are devices that brake the vehicle by pinching the disks 15L, 15R to generate braking force. In FIG. 1, only the left wheel LW and the right wheel RW constituting the front wheel side of the automobile are shown, and the rear wheel side is not shown, but the rear wheel side is also the front wheel side (left The wheel LW and the right wheel RW) can have the same configuration or other configurations. Further, in the brake device 10 according to the present embodiment, reference numerals of those provided on the left wheel LW side are denoted by “L”, reference numerals of those provided on the right wheel RW side are denoted by “R”, When the left wheel LW side and the right wheel RW side are described together, the above “L” and “R” are omitted.

  The brake device 10 generates a braking force by a pedal 12 that is operated by a driver according to a driving condition, a master cylinder 16 that is driven in conjunction with the operation of the pedal 12, and the braking force generators 14L and 14R. Motor cylinders (hydraulic pressure generating units, caliper cylinders) 18L and 18R for applying a hydraulic pressure for the purpose. Each component of the brake device 10 is electrically connected to and controlled by the ECU 20 that is a control unit.

  That is, the brake device 10 includes a hydraulic pressure (hydraulic pressure) system that connects hydraulic pressure (hydraulic pressure) between the components and an electric system that electrically connects the components and the ECU 20. The In FIG. 1, a path (flow path) constituting the hydraulic system is indicated by a solid line, and a path (signal line) constituting the electrical system is indicated by a broken line. Examples of the liquid filled in the hydraulic system include brake fluid.

  As shown in FIG. 1, the pedal 12 is provided with a pedal operation information detection unit 22 that detects a force by which the driver depresses the pedal 12 (stepping force) and an amount (stroke) of the pedal 12 operated by the driver. The detection value of the pedal operation information detection unit 22 is input to the ECU 20. For example, a torque sensor provided on the tread surface of the pedal 12 is used for the detection of the pedal force, and a potentiometer or an encoder for detecting the rotation angle of the pedal 12 is used for the detection of the stroke, for example. Note that the pedal operation information detection unit 22 may be configured to detect only the pedal effort.

  An electric actuator (actuator, reaction force motor) 24 is connected to the vicinity of the swing shaft on the base end side of the pedal 12. The electric actuator 24 adjusts the reaction force against the depression of the driver's pedal 12 and the position of the pedal 12 under the control of the ECU 20. The electric actuator 24 can apply torque to the pedal 12, that is, the electric actuator 24 may also function as a pedal operation information detection unit 22 that detects the pedaling force of the pedal 12.

  The master cylinder 16 includes two pistons 26L and 26R arranged in order in the axial direction, a rod 28 whose rear end is connected to the pedal 12 to drive the pistons 26L and 26R forward and backward, and the inside of the cylinder 16a is the piston 26L, It is composed of two pressurizing chambers 30L and 30R that are partitioned by 26R. The pressurizing chambers 30L and 30R are provided with return springs (elastic members) 32L and 32R that return the pistons 26L and 26R that have been moved by the depression of the pedal 12 to their original positions.

  The pressurizing chambers 30L and 30R are connected to the braking force generators 14L and 14R by main paths 33L and 33R.

  The motor cylinders 18L, 18R can drive the pistons 38L, 38R forward and backward within the cylinders 40L, 40R by connecting the rear ends of the rods 34L, 34R to brake motors (caliper motors) 36L, 36R. The pressurizing chambers 42L, 42R constituting the motor cylinders 18L, 18R are connected to the main paths 33L, 33R via the paths 44L, 44R. That is, the pressurizing chamber 42 of the motor cylinder 18 is connected to the braking force generator 14.

  In the main paths 33L and 33R, pedal simulators (PS) 48L and 48R are connected to the master cylinder 16 side of the paths 44L and 44R via the paths 46L and 46R. The pedal simulators 48 </ b> L and 48 </ b> R have repulsion springs (elastic members) 50 </ b> L and 50 </ b> R and have a function of generating a reaction force against the hydraulic pressure from the master cylinder 16.

  The pressure chambers 30L and 30R of the master cylinder 16 communicate with paths 54L and 54R connected to the reservoir tank 52. The reservoir tank 52 functions to adjust the hydraulic pressure (fluid amount) of the hydraulic system of the brake device 10. Furthermore, auxiliary paths 56L and 56R communicating with the pressurizing chambers 42L and 42R of the motor cylinders 18L and 18R are connected to the reservoir tank 52. The paths 54L and 54R and the auxiliary paths 56L and 56R merge before being connected to the reservoir tank 52, respectively.

  In the path 54 connected to the reservoir tank 52, the opening communicating with the pressurizing chamber 30 is formed close to the original position of the piston 26. As a result, when the pistons 26L and 26R advance from their original positions (if they move slightly), the opening is closed, that is, the paths 54L and 54R are blocked between the pressurizing chambers 30L and 30R and the reservoir tank 52. Is done. The auxiliary route 56 is configured in substantially the same manner as the route 54 described above. That is, at the same time as the pistons 38L and 38R advance from their original positions, the auxiliary paths 56L and 56R are blocked between the pressurizing chambers 42L and 42R and the reservoir tank 52.

  In such a brake device 10, master cylinder pressure sensors 58L, 58R, fail-safe valves 60L, 60R, brake pressure sensors (caliper pressure sensors) are provided in the main paths 33L, 33R in order from the pressurizing chambers 30L, 30R side. ) 62L and 62R are disposed. Brake valves (caliper valves) 64L and 64R are disposed in the paths 44L and 44R. Simulator valves (PS valves) 66L and 66R are disposed in the paths 46L and 46R.

  The fail-safe valve 60 is provided between the main path 33 and the connecting part of the path 44 and the connecting part of the path 46. When the solenoid 60a is excited (driven) under the control of the ECU 20, the main path 33 is provided. Communicating or blocking Similarly, under the control of the ECU 20, the brake valve 64 communicates or blocks the path 44 when the solenoid 64a is excited, and the simulator valve 66 communicates or blocks the path 46 when the solenoid 66a is excited.

  In FIG. 1, for the sake of simplicity, the signal lines connected from the master cylinder pressure sensor 58 and the brake pressure sensor 62 to the ECU 20 and the signal lines connected from the solenoids 60a, 64a, 66a to the ECU 20 are omitted. Yes.

  In the brake device 10 configured as described above, the operation information of the pedal 12 is normally detected by the pedal operation information detection unit 22 and input to the ECU 20 at the normal time. Then, the motor cylinder 18 is driven based on a command from the ECU 20, the braking force is generated by the braking force generator 14, and a braking operation is performed. That is, the brake device 10 is configured as a system (brake-by-wire) that employs the by-wire technology.

  Then, next, the fundamental operation | movement and effect of the brake device 10 which concern on this embodiment are demonstrated.

  First, the normal time (when the system is on) when the brake device 10 is driven and controlled as brake-by-wire will be described.

  When the system is on, first, the brake valve 64 and the simulator valve 66 are opened and the failsafe valve 60 is closed under the control of the ECU 20. As a result, the path 44 connecting the motor cylinder 18 and the braking force generator 14 communicates, and the path 46 (including a part of the main path 33) connecting the master cylinder 16 and the pedal simulator 48 communicates. And the main path 33 connecting the braking force generator 14 is blocked.

  When the driver operates the pedal 12 in this state, the hydraulic pressure generated in the pressurizing chamber 30 of the master cylinder 16 is applied to the pedal simulator 48 by the operation of the pedal 12, and a reaction force is generated in the pedal simulator 48. Thus, the basic characteristics of the pedal force and stroke of the pedal 12 are determined. However, the basic characteristic (pedal simulator characteristic) is based on the reaction force generated by the repulsion spring 50 of the pedal simulator 48, and is linear in the relationship between the pedaling force and the stroke, as indicated by the broken line in FIG. It has become. Therefore, in the brake device 10, the electric actuator 24 is driven based on the pedaling force (operation torque) detected by the pedal operation information detecting unit 22, and the pedaling force and the stroke characteristics are optimized by the reaction force generated by the electric actuator 24 ( (Indicated by a solid line in FIG. 2). Thus, the driver can operate the pedal 12 with an optimal feeling.

  At the same time, by the driver's operation of the pedal 12, operation information (stepping force and stroke) of the pedal 12 is input to the ECU 20 from the pedal operation information detection unit 22, and the ECU 20 includes the input operation information (operation information of the pedal 12). Based on this, the motor cylinder 18 is driven and controlled. Accordingly, the hydraulic pressure generated in the motor cylinder 18 is applied to the braking force generator 14, and the braking force is generated in the braking force generator 14 to brake the left wheel LW and the right wheel RW.

  Second, a state where the brake device 10 is not driven and controlled as brake-by-wire (when the system is off) will be described. Examples of the system off time include a so-called failure time such as when the electric actuator 24 fails or malfunctions, or when the system is stopped when the ignition is off.

  When the system is off, first, the fail safe valve 60 is opened and the brake valve 64 and the simulator valve 66 are closed under the control of the ECU 20 (see FIG. 1). As a result, the main path 33 connecting the master cylinder 16 and the braking force generation unit 14 communicates, the path 44 connecting the motor cylinder 18 and the braking force generation unit 14 is blocked, and the master cylinder 16 and the pedal simulator 48 are connected. Path 46 is blocked.

  When the driver operates the pedal 12 in this state, the hydraulic pressure generated in the pressurizing chamber 30 of the master cylinder 16 by the operation of the pedal 12 is applied to the braking force generation unit 14 and is controlled by the braking force generation unit 14. Power is generated and the left wheel LW and the right wheel RW are braked. Since the reaction force to the pedal 12 can be obtained by the master cylinder 16, the driver can operate the pedal 12 with certainty.

  Thirdly, the case where the initial position of the pedal 12 is changed in the brake device 10 will be described. The initial position change of the pedal 12 is performed, for example, when the initial position (original position) of the pedal 12 in the front-rear (swinging) direction is changed according to the physique of the driver.

  When changing the initial position of the pedal 12, first, when the driver turns on the position change switch 68, the fail safe valve 60 and the brake valve 64 are opened and the simulator valve 66 is closed under the control of the ECU 20. As a result, the main path 33 connecting the master cylinder 16 and the braking force generation unit 14 communicates, and the path 44 connecting the motor cylinder 18 and the braking force generation unit 14 communicates, and connects the master cylinder 16 and the pedal simulator 48. Path 46 is blocked.

  When the driver operates the position change switch 68 in this state, the electric actuator 24 is driven and the pedal 12 moves under the control of the ECU 20. Accordingly, the initial position of the pedal 12 is determined by the driver operating the position change switch 68 with the pedal 12 at the desired position. In addition, the operation | movement which makes the pedal 12 a desired position can also be comprised so that a driver | operator may directly operate and move the pedal 12 besides performing with the electric actuator 24. FIG.

  When the initial position of the pedal 12 is changed, the piston 26 of the master cylinder 16 also moves as the pedal 12 is moved by the electric actuator 24. However, the hydraulic pressure (fluid amount) corresponding to the movement of the piston 26 is sent from the main path 33 to the pressurizing chamber 42 of the motor cylinder 18 via the brake valve 64, and to the reservoir tank 52 via the auxiliary path 56. Will be returned. In this case, since the simulator valve 66 is closed, no reaction force is generated in the pedal simulator 48, and only the reaction force from the return spring 32 of the master cylinder 16 acts on the pedal 12. 24 does not require a large capacity.

  Even when the brake device 10 is driven and controlled as a brake-by-wire (system on) after the change of the initial position of the pedal 12 is completed, the hydraulic system adjusted by the reservoir tank 52 at the time of the initial position change Fluid pressure (fluid amount) is maintained. As a result, the changed initial position of the pedal 12 can be reliably held. Moreover, since the reaction force acting on the pedal 12 after the initial position change is only a minute force from the return spring 32 of the master cylinder 16, an electric motor for maintaining the initial position of the pedal 12 after the position change is performed. The power consumption of the actuator 24 is extremely small. In other words, the capacity of the electric actuator 24 can be further reduced.

  As described above, in the brake device 10 according to the present embodiment, the ECU 20 includes the pedal optimum reaction force calculation unit that calculates the optimum reaction force to the pedal 12, and the pedal initial position that changes and sets the initial position of the pedal 12. It has functions as a setting unit, a braking force determination unit that determines the braking force of the vehicle, and a valve operation mode setting unit that sets the operation of each valve (see FIG. 3).

  Also, according to the brake device 10, when the system is driven and controlled as a brake-by-wire, the reaction force of the pedal simulator 48 is used as a reaction force when the pedal 12 is operated, and the electric actuator 24 uses the reaction force. It performs the function of correcting and optimizing. Therefore, it is not necessary to generate all the reaction force only with the electric actuator 24, and the electric actuator 24 can be of a small capacity.

  In the brake device 10, it is possible to generate the braking force at the braking force generator 14 through the master cylinder 16 by operating the pedal 12 even when the system is off, such as when a failure occurs.

  In the brake device 10, when the initial position of the pedal 12 is changed, the hydraulic pressure (fluid amount) of the movement of the piston 26 of the master cylinder 16 that has moved with the movement of the pedal 12 is transferred from the auxiliary path 56 to the reservoir tank. 52. Accordingly, even when the brake device 10 is turned on after the initial position change of the pedal 12 is completed, in the hydraulic system, in the hydraulic system, the hydraulic pressure (liquid level) adjusted by the reservoir tank 52 at the time of the initial position change Amount) is held, and the initial position of the pedal 12 can be reliably held. In addition, the reaction force acting on the pedal 12 after the initial position change is only a minute reaction force from the return spring 32 of the master cylinder 16, so the power consumption of the electric actuator 24 required to hold the initial position of the pedal 12 is reduced. Therefore, the capacity of the electric actuator 24 can be further reduced.

  In addition to adjusting the hydraulic pressure when the position of the pedal 12 is changed, the auxiliary path 56 supplements the hydraulic pressure (fluid amount) from the reservoir tank 52 to the motor cylinder 18 that has been lowered by driving the motor cylinder 18. It is also used when

  In the brake device 10 according to the above embodiment, a hydraulic (hydraulic) pump may be used in place of the motor cylinder 18 as a hydraulic pressure generating unit that applies hydraulic pressure to the braking force generating unit 14.

  The pedal simulators 48L and 48R may be shared on the left wheel LW side and the right wheel RW side.

  The braking force generator 14 may be a wheel cylinder that causes a shoe to come into contact with the drum as a drum brake, in addition to a caliper that holds the disc 15 as a so-called disc brake.

  As described above, the present invention has been described with the embodiment. However, the present invention is not limited to this, and it is naturally possible to adopt various configurations without departing from the gist of the present invention.

It is a block circuit diagram of a brake device concerning one embodiment of the present invention. It is a graph which shows the relationship between the pedal effort and stroke. It is a block block diagram which shows typically the electric system of the brake device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Brake apparatus 12 ... Pedal 14L, 14R ... Braking force generation part 16 ... Master cylinder 18L, 18R ... Motor cylinder 20 ... ECU
24 ... Electric actuators 33L, 33R ... Main paths 44L, 44R, 46L, 46R, 54L, 54R ... Paths 48L, 48R ... Pedal simulator 52 ... Reservoir tanks 56L, 56R ... Auxiliary paths 60L, 60R ... Fail safe valves 64L, 64R ... Brake valve 66L, 66R ... Simulator valve

Claims (2)

A master cylinder connected to the brake pedal and generating hydraulic pressure by operating the brake pedal;
A hydraulic pressure generating unit that generates hydraulic pressure based on operation information of the brake pedal;
A braking force generator that generates a brake braking force by the hydraulic pressure generated by the master cylinder or the hydraulic pressure generator;
A pedal simulator that communicates with the master cylinder and generates a reaction force on the brake pedal by the hydraulic pressure generated by the master cylinder;
A fail-safe valve for communicating or blocking a main path between the master cylinder and the braking force generator;
A simulator valve for communicating or blocking a path between the main path and the pedal simulator;
A brake device comprising a brake valve for communicating or blocking a path between the main path and the hydraulic pressure generating unit,
An actuator coupled to the brake pedal for adjusting the position of the brake pedal;
An auxiliary path that communicates the braking force generator and the hydraulic pressure adjusting reservoir tank;
With
When adjusting the position of the brake pedal by the actuator, the brake device is characterized in that the fail-safe valve and the brake valve are in communication and the simulator valve is shut off. The brake device according to claim 1, wherein
The hydraulic pressure generating unit is communicated with the braking force generating unit via the brake valve, and the auxiliary path is communicated between the hydraulic pressure generating unit and the reservoir tank. Brake device.

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