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US 6,332,654 B1Granted
Grade-holding brake system
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorTakuto Yano
Life of this patent
Estimating the term…
Abstract
In most vehicles, it is necessary to manually operate the parking brake whenever the vehicle is stopped. The manual brake operation is fatiguing and liable to make the driver feel that the operation is troublesome. A controller 10 controls a cut-off valve 8 to close in a vehicle stopping condition, and even if a brake pedal 1 is released, a pressure within a wheel cylinder 6 is held to thereby maintain a braking force. Also, when an accelerator pedal 11 is depressed when the brake hydraulic pressure is maintained within the wheel cylinder 6, the controller 10 controls the cut-off valve 8 in the open condition so that the pressure within the wheel cylinder 6 is reduced to release the brake.
Claims19
A grade-holding brake system for a vehicle comprising:
- a master cylinder connected to a booster device for amplifying a brake force applied by a driver to a brake pedal;
- a wheel cylinder for converting a pressure fed from said master cylinder into a braking force for a wheel;
- a brake switch for detecting an amount of depression of said brake pedal;
- an accelerator switch for detecting an amount of depression of an accelerator pedal;
- a vehicle speed sensor for detecting a speed of a vehicle on which said system is mounted;
- a wheel cylinder pressure detector for detecting the pressure within said wheel cylinder;
- and
- a pressure increase means controlled by said controller for increasing the pressure within said wheel cylinder independent of the operation of the brake pedal;
- a pressure controlling means for controlling the pressure within said wheel cylinder independent of the operation of the brake pedal;
- and
- a controller for controlling actuation of said pressure controlling means for controlling the pressure within said wheel cylinder,
- wherein said controller performs:
- a brake pedal depression detecting step for detecting whether said brake pedal is being depressed or not on the basis of a detection signal of said brake switch;
- an accelerator pedal depression detecting step for detecting whether said accelerator pedal is being depressed on the basis of a detection signal of said accelerator switch;
- a vehicle halted determination step for determining a vehicle-halted state of the vehicle on the basis of a detection signal of said vehicle speed sensor;
- a holding condition establishment step for establishing a brake holding condition for holding a braked condition of a brake at least when the brake pedal is depressed and when the vehicle is in the vehicle halted condition;
- a holding condition release step for establishing a brake release condition for releasing the braked condition of the brake at least when the accelerator pedal is depressed;
- a first holding command step for sending a pressure holding command to said pressure controlling means and maintaining the pressure within said wheel cylinder until the brake release condition is established when the brake holding condition is established and when the brake release condition is not established;
- a pressure decrease command step for sending a pressure decrease command to said pressure controlling means to decrease the pressure within said wheel cylinder to thereby release the brake when the brake release condition is established;
- a target pressure setting step for setting a target pressure within said wheel cylinder to obtain a target braking force;
- a comparative determination step for determining a difference between a detected pressure of said wheel cylinder pressure detector and the target pressure;
- and
- a second holding command step for, when the brake holding operation by said pressure controlling means is established and when the brake release condition is not established, performing said first holding command step when the detected pressure is higher than the target pressure, and for increasing the pressure within said wheel cylinder up to the target pressure by said pressure increasing means, and at the same time, maintaining the pressure within said wheel cylinder until the brake release condition is established when the detected pressure is lower than the target pressure.
20 more elements
A grade-holding brake system for a vehicle comprising:
- a master cylinder connected to a booster device for amplifying a brake force applied by a driver to a brake pedal;
- a wheel cylinder for converting a pressure fed from said master cylinder into a braking force for a wheel;
- a brake switch for detecting an amount of depression of said brake pedal;
- an accelerator switch for detecting an amount of depression of an accelerator pedal;
- a vehicle speed sensor for detecting a speed of a vehicle on which said system is mounted;
- a pressure controlling means for controlling the pressure within said wheel cylinder independent of the operation of the brake pedal;
- and
- a controller for controlling actuation of said pressure controlling means for controlling the pressure within said wheel cylinder,
- wherein said controller performs:
- a brake pedal depression detecting step for detecting whether said brake pedal is being depressed or not on the basis of a detection signal of said brake switch;
- an accelerator pedal depression detecting step for detecting whether said accelerator pedal is being depressed on the basis of a detection signal of said accelerator switch;
- a vehicle halted determination step for determining a vehicle-halted state of the vehicle on the basis of a detection signal of said vehicle speed sensor;
- a holding condition establishment step for establishing a brake holding condition for holding a braked condition of a brake at least when the brake pedal is depressed and when the vehicle is in the vehicle halted condition;
- a holding condition release step for establishing a brake release condition for releasing the braked condition of the brake at least when the accelerator pedal is depressed;
- a first holding command step for sending a pressure holding command to said pressure controlling means and maintaining the pressure within said wheel cylinder until the brake release condition is established when the brake holding condition is established and when the brake release condition is not established;
- and
- a pressure decrease command step for sending a pressure decrease command to said pressure controlling means to decrease the pressure within said wheel cylinder to thereby release the brake when the brake release condition is established,
- wherein one of said brake depressing amount detecting step and said brake re-depress detecting step, for detecting that the brake pedal has been depressed again when the first and/or second holding command step(s) is/arc executed and the brake pedal is released, is preformed by a master cylinder pressure detector for detecting a pressure at a location closer to the master cylinder than said first cut-off valve.
15 more elements
Dependencies are inferred from the claim text.