Abstract:
A hydraulic brake system includes: a master cylinder including a pressurizing piston; a brake cylinder for a hydraulic brake operable by a hydraulic pressure in a front pressure chamber defined in front of the pressurizing piston; and a rear-hydraulic pressure controller connected to a rear chamber defined at a rear of the pressurizing piston. The rear-hydraulic pressure controller controls a hydraulic pressure in the rear chamber and includes: a regulator, operable by at least one of the hydraulic pressure in the front pressure chamber and a control pressure controlled electrically, for supplying an output hydraulic pressure to the rear chamber; and a master-pressure-operating-state detector configured to, when the output hydraulic pressure is greater than a threshold value, detect that the regulator is in a master-pressure operating state in which the regulator is operated by at least the hydraulic pressure in the front pressure chamber.
Abstract:
A spool valve V1 includes a valve element 11 and a cylinder 12 having a bore 12a which accommodates the valve element 11 to be movable in an axial direction. In this spool valve V1, when the valve element 11 in an initial position moves in the axial direction in relation to the cylinder 12, a supply valve port Vi formed between the valve element 11 and the cylinder 12 opens, whereby a working fluid is introduced from a hydraulic pressure source into a hydraulic chamber through the supply valve port Vi. A throttle portion O1 is provided in a fluid channel formed on the hydraulic chamber side of the supply valve port Vi. The throttle portion O1 is configured such that in a throttle valid region which extends from the initial position to a position where the amount of axial movement of the valve element 11 from the initial position becomes equal to a predetermined value, the area of the opening formed between the valve element 11 and the cylinder 12 is constant, and in a throttle invalid region where the amount of axial movement of the valve element 11 exceeds the predetermined value, the area of the opening increases. Thus, it becomes possible to restrain occurrence of oil impact within the hydraulic chamber to which the working fluid is supplied through the spool valve V1.
Abstract:
A braking device for a vehicle is provided which includes a hydraulic booster to make wheels of the vehicle produce frictional braking force. The hydraulic booster includes a fluid chamber and a throttle. When a brake pedal is depressed suddenly, the throttle works to obstruct or restrict an outflow of brake fluid from the fluid chamber, thereby increasing the pressure in the fluid chamber. This causes the pressure in a master chamber of the hydraulic booster to rise, thereby producing the frictional braking force almost no later than start of the depression of the brake pedal.
Abstract:
A reservoir container has a reservoir, and a communicating passage that guides brake fluid to the reservoir. The reservoir of the reservoir container that accumulate the brake fluid is made to a hole extending in a transverse direction so that a size of the reservoir container in a height direction is made small while fully securing the capacity of the reservoir. Moreover, a horizontal plane projected area of the communicating passage is made smaller than that of the reservoir, so that a sealing part of the communicating passage is shortened, and ensures the seal integrity.
Abstract:
Provided is an electric parking brake device in which a parking lever is driven by an electric actuator. The electric actuator includes: an electric motor which can be rotationally driven in a normal/reverse direction and of which an operation is controlled by a motor control unit in accordance with rotational loads; a converting mechanism which can convert a rotational movement into a linear movement and which can move the parking lever from a returning position to an operating position in accordance with normal rotation of the electric motor and which can move the parking lever from the operating position to the returning position in accordance with reverse rotation of the electric motor; and a load applying mechanism (a stopper, a friction material) which drives components of the converting mechanism and which applies predetermined rotational loads to the electric motor, in a state where the parking lever is moved from the operating position to the returning position in accordance with reverse rotation of the electric motor.
Abstract:
A vehicle brake device is provided with a regulator for generating a servo pressure acting on a master piston in a master cylinder, based on a pilot pressure. The regulator is provided with a brake fluid absorbing section communicating with a first pilot chamber for absorbing the brake fluid as the pilot pressure in the first pilot chamber in the quantity depending on the fluid pressure in the first pilot chamber. The brake fluid absorbing section comprises a piston receiving portion formed in a second piston and opening to the first pilot chamber, a pressure receiving piston slidably received in the piston receiving portion and making the first pilot chamber variable in capacity, and an urging member urging the pressure receiving piston toward the first pilot chamber side.
Abstract:
A vehicle brake system includes a cylinder, a master piston including a pressure applying piston and a projection portion, a servo chamber, a contact/separation determining means determining a separated state and a contact state between the input piston and the master piston, a pilot pressure generating device generating a pilot pressure, a servo pressure generating device, a servo pressure measuring device measuring a servo pressure, and a master pressure estimating means estimating a master pressure from the pilot pressure and a first servo ratio, which is a cross-sectional area ratio between a first pilot chamber and a servo pressure generating chamber, in a case of the separated state, and estimating the master pressure based on the servo pressure, the pilot pressure and a second servo ratio, which is a cross-sectional area ratio between a second pilot chamber and the servo pressure generating chamber, in a case of the contact state.
Abstract:
Each of a plurality of electric brake devices corresponds to one of a plurality of wheels and includes a motor. A brake ECU, which controls the electric brake devices, determines whether there is an overheated motor of which the temperature T is greater than or equal to a first set threshold value Tth1. Also, when there is only one overheated motor, the brake ECU reduces a current value Ix for the overheated motor at a more gradual gradient in the case where the temperature T of the overheated motor is low than in the case where the temperature is high.
Abstract:
A motion control device for a vehicle, including a braking means for applying a brake torque to a wheel of the vehicle and maintaining a traveling stability of the vehicle by controlling the braking means, the motion control device for the vehicle, includes a steering angular velocity obtaining means for obtaining a steering angular velocity of the vehicle, a yaw angular acceleration obtaining means for obtaining a yaw angular acceleration of the vehicle, and a control means for controlling the brake torque on the basis of the steering angular velocity and the yaw angular acceleration.
Abstract:
A motion control device for a vehicle includes a braking means for applying a brake torque to each of a plurality of wheels of the vehicle, an avoidance control means for calculating a first target quantity, used for an avoidance control for applying the brake torque to each wheel via the braking means in order to avoid an emergency state of the vehicle, a stabilization control means for determining a target wheel, to which the brake torque is applied, out of the wheels and calculating a second target quantity used for a stabilization control for applying the brake torque to the target wheel in order to ensure a vehicle stability, and a brake control means for controlling the brake torque applied to a non-target wheel based on the first target quantity and controlling the brake torque applied to the target wheel based on the first and second target quantities.