摘要:
When a brake switch is switched from OFF to ON, current is applied to a brake ECU, and a command to switch a master cylinder from a second state to a first state is issued after a lapse of preparation time, so that switching-time change suppression control is performed. A reservoir shutoff valve is closed, and duty control is performed on a communication control valve. The duty ratio is set to 1 when a switching-time control duration expires, and the communication control valve is placed in an open position, to establish the first state. Thus, since the communication control valve is duty-controlled during switching from the second state to the first state, change in the hydraulic pressure of an input chamber is suppressed, and change of the operating feeling is suppressed.
摘要:
A hydraulic-pressure control device includes: a regulator (182) including a housing (200), a control piston (204) in the housing (200); an input chamber (212) at a rear of the control piston (204) and an output chamber (214) in front of the control piston (204); and an input-hydraulic-pressure control device (56,184) which controls hydraulic pressure in the input chamber (212) to move the control piston (204) forward or backward to raise or reduce hydraulic pressure in the output chamber (214). According to the first invention, the hydraulic-pressure control device further includes: a moving-direction control unit which, when a difference obtained by subtracting an actual hydraulic pressure in the output chamber (214) from a target hydraulic pressure in the output chamber (214) is less than a pressurization-side set value, controls the hydraulic pressure in the input chamber (212) to move the control piston (204) backward and, when the difference is greater than a reduction-side set value, controls the hydraulic pressure in the input chamber (212) to move the control piston (204) forward. According to the second invention, the hydraulic-pressure control device further includes: a cylinder device (66) comprising a housing (100), a pressurizing piston (102, 104) fluid-tightly and slidably fitted in the housing, a rear chamber (136) provided at a rear of the pressurizing piston and coupled to the output chamber (214), a front pressure chamber (110, 112) provided in front of the pressurizing piston (102,104) and a brake cylinder (42, 52), coupled to the front pressure chamber, for a hydraulic brake (40, 50) capable of restraining rotation of a wheel (4, 46) of a vehicle, wherein the input-hydraulic-pressure control device (56,184) comprises a sliding-resistance-related pressure control unit configured to control the hydraulic pressure in the input chamber (212) with consideration of a sliding resistance caused between the control piston (204) and the housing (200) of the regulator (182).
摘要:
A hydraulic braking system includes: a cylinder device including a pressurizing piston, a rear chamber, and a front pressure chamber on opposite sides of the pressurizing piston; a brake cylinder coupled to the front pressure chamber; a regulator including a control piston, an input chamber provided at a rear of the control piston, and an output chamber coupled to the rear chamber in front of the control piston; and an input-hydraulic-pressure control device including a high-flow-rate supply unit configured, when an operation of the regulator is started, to supply the working fluid to the input chamber at a set flow rate; and a low-flow-rate supply unit configured, when the supply is finished, to supply the working fluid to the input chamber at a flow rate less than the set flow rate.
摘要:
In a hydraulic brake system including a cylinder device that includes a front chamber and a rear chamber located on front and rear sides of a pressurizing piston, respectively, presence or absence of liquid leakage from a brake line is detected based on a hydraulic pressure in the rear chamber. Where a state in which a subtraction value obtained by subtracting an actual rear hydraulic pressure from a target rear hydraulic pressure is larger than a first malfunction determination threshold value has continued for a time not shorter than a first malfunction determination time, and then an increase of the actual rear hydraulic pressure at a rate not lower than a set rate has caused the subtraction value to become smaller than a return determination threshold value, it is determined that the pressurizing piston has been bottomed due to liquid leakage from the front chamber.
摘要:
In a hydraulic brake system including a cylinder device that includes a front chamber and a rear chamber located on front and rear sides of a pressurizing piston, respectively, presence or absence of liquid leakage from a brake line is detected based on a hydraulic pressure in the rear chamber. Where a state in which a subtraction value obtained by subtracting an actual rear hydraulic pressure from a target rear hydraulic pressure is larger than a first malfunction determination threshold value has continued for a time not shorter than a first malfunction determination time, and then an increase of the actual rear hydraulic pressure at a rate not lower than a set rate has caused the subtraction value to become smaller than a return determination threshold value, it is determined that the pressurizing piston has been bottomed due to liquid leakage from the front chamber.
摘要:
A hydraulic-pressure control device includes a regulator including a housing, a control piston in the housing, an input chamber at a rear of the piston, and an output chamber in front of the piston; and an input-hydraulic-pressure control device which controls hydraulic pressure in the input chamber to move the piston forward or backward to raise or reduce hydraulic pressure in the output chamber. The input-hydraulic-pressure control device includes a moving-direction control unit which, when a difference obtained by subtracting an actual hydraulic pressure in the output chamber from a target hydraulic pressure in the output chamber is less than a pressurization-side set value, controls the hydraulic pressure in the input chamber to move the piston backward; and when the difference is greater than a reduction-side set value, controls the hydraulic pressure in the input chamber to move the piston forward.
摘要:
When a brake switch is switched from OFF to ON, current is applied to a brake ECU, and a command to switch a master cylinder from a second state to a first state is issued after a lapse of preparation time, so that switching-time change suppression control is performed. A reservoir shutoff valve is closed, and duty control is performed on a communication control valve. The duty ratio is set to 1 when a switching-time control duration expires, and the communication control valve is placed in an open position, to establish the first state. Thus, since the communication control valve is duty-controlled during switching from the second state to the first state, change in the hydraulic pressure of an input chamber is suppressed, and change of the operating feeling is suppressed.
摘要:
A pressure regulator, including a housing; a piston axially movably disposed in the housing; a high-pressure chamber; a low-pressure chamber; a regulated-pressure chamber whose pressure biases the piston in a first direction in an axial direction of the housing; a first pilot chamber whose pressure biases the piston in a second direction opposite to the first direction; a second pilot chamber whose pressure biases the piston in the second direction; and a valve mechanism configured such that, by a movement of the piston in the second direction, communication between the regulated-pressure chamber and the high-pressure chamber is permitted while communication between the regulated-pressure chamber and the low-pressure chamber is shut off and such that, by a movement of the piston in the first direction, the communication between the regulated-pressure chamber and the high-pressure chamber is shut off while the communication between the regulated-pressure chamber and the low-pressure chamber is permitted.
摘要:
A device for controlling the slip between driving wheels and a road surface during a start and an acceleration of a vehicle is maintained at a level which ensures a good acceleration and straight line running stability. The device determines a target speed of the rotation of the driving wheels, and controls a drive torque of the driving wheels in such a manner that the actual speed of the rotation of the driving wheels coincides with the target speed. Also, the device detects a friction coefficient between the driving wheels and the road surface, and the slippage of the driving wheels is controlled on the basis of the friction coefficient. Further, the device determines the reliability of the detected friction coefficient, and uses the detected friction coefficient only when the detected friction coefficient is determined to be reliable.
摘要:
An on-board camera is disposed, behind a neighboring member that is located above a steering column, on the steering column that can move forward at the time of a collision of a vehicle in which the on-board camera is installed. The on-board camera includes: a camera portion; and a support mechanism. The support mechanism supports the camera portion in such a manner that the camera portion can move in a direction away from the neighboring member when the neighboring member and the camera portion are brought into contact with each other because of a forward movement of the steering column at the time of the collision.