Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
  • B60T8/36—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition including a pilot valve responding to an electromagnetic force
  • B60T8/3615—Electromagnetic valves specially adapted for anti-lock brake and traction control systems
  • B60T8/3655—Continuously controlled electromagnetic valves
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T13/00—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems
  • B60T13/10—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release
  • B60T13/12—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid
  • B60T13/14—Transmitting braking action from initiating means to ultimate brake actuator with power assistance or drive; Brake systems incorporating such transmitting means, e.g. air-pressure brake systems with fluid assistance, drive, or release the fluid being liquid using accumulators or reservoirs fed by pumps
  • B60T13/148—Arrangements for pressure supply
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/321—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration deceleration
  • B60T8/328—Systems sharing components with other fluid systems onboard the vehicle
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
  • B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
  • B60T8/404—Control of the pump unit
  • B60T8/4045—Control of the pump unit involving ON/OFF switching
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
  • B60T8/44—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition co-operating with a power-assist booster means associated with a master cylinder for controlling the release and reapplication of brake pressure through an interaction with the power assist device, i.e. open systems
  • B60T8/441—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition co-operating with a power-assist booster means associated with a master cylinder for controlling the release and reapplication of brake pressure through an interaction with the power assist device, i.e. open systems using hydraulic boosters
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B60—VEHICLES IN GENERAL
  • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
  • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
  • B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
  • B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
  • B60T8/48—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition connecting the brake actuator to an alternative or additional source of fluid pressure, e.g. traction control systems
  • B60T8/4809—Traction control, stability control, using both the wheel brakes and other automatic braking systems
  • B60T8/4827—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems
  • B60T8/4863—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems closed systems
  • B60T8/4872—Traction control, stability control, using both the wheel brakes and other automatic braking systems in hydraulic brake systems closed systems pump-back systems

Definitions

• the invention has for its object to provide a control of a hydraulic amplifier with little technical effort, which enables safe and comfortable hydraulic brake power assistance.
• the object is accordingly achieved in that the hydraulic pressure is controlled directly into a master brake cylinder via an upstream hydraulic booster, and in that the hydraulic pressure is regulated in accordance with a variable representative of the driver's brake request by regulating the pressure in the upstream hydraulic booster at least two analog or analog valves is controlled.
• An analog or analog valve can take all positions between "OPEN ⁇ and" CLOSED by means of an electrical or electronic external control, so that the brake pressure for. Control or comfort braking can be continuously increased or decreased.
• the analog or analogized valve is preferably set with a current value.
• the master brake cylinder is preferably a two-circuit system and is designed in particular as a tandem master cylinder (THZ).
• TTZ tandem master cylinder
• the hydraulic pressure in the upstream hydraulic booster by controlling a first analog or analogized valve, which leads the pressure fluid away from the hydraulic booster into a
• Regulates pressure medium reservoir and is controlled by controlling a second analog or analog valve, which regulates the supply of the pressure fluid from an external pressure source in the hydraulic amplifier.
• the pressure medium reservoir is preferably designed to be depressurized.
• the pressure of the external pressure source is generated by controlling a motor of a motor-pump unit and is stored in a hydraulic high-pressure accumulator.
• a hydraulic return pump or a return motor pump unit that is already present in a braking system is preferably used.
• the analog or analogized valves are actuated for the purpose of applying a specific hydraulic pressure to an booster piston of the hydraulic booster, which is driven into the wheel brakes of the vehicle via a master brake cylinder piston that is operatively connected to the booster piston in the direction of force output.
• the brake pressure is regulated and / or the hydraulic pressure builds up in the high-pressure accumulator by controlling electronically controllable valves.
• a hydraulic pressure can be introduced into the brake system by the driver through a direct operative connection of the upstream hydraulic booster with a brake pedal.
• the system can ensure an emergency braking function in the event of a failure.
• the pedal travel of a brake pedal and / or a variable derived from the pedal travel is used for the driver brake request detection.
• the pedal travel of the brake pedal and / or a variable derived therefrom is used as a variable that represents the driver's braking request.
• the pressure in the upstream hydraulic booster is based a measured hydraulic pressure in the master brake cylinder is determined or estimated.
• the pressure in the hydraulic high-pressure accumulator is monitored by a pressure sensor.
• the charging process of the hydraulic high-pressure accumulator begins before a lower switching point of a pressure sensor on the high-pressure accumulator is reached.
• the hydraulic high-pressure accumulator is charged in phases of increasing and / or constant engine load of the drive motor of the vehicle.
• the charging process of the hydraulic high-pressure accumulator is interrupted when the brakes are applied and / or an engine load of the drive motor of the vehicle.
• the hydraulic high-pressure accumulator (4) is charged when the engine load of the drive motor of the vehicle is equal to zero (0) or less than 0 ( ⁇ 0), ie when the drive motor is being towed, and / or when the vehicle is at a substantially constant speed.
• an additional pressure increase by means of a pressure increase unit, preferably a hydraulic pump, takes place when the control point of the hydraulic amplifier is exceeded.
• the amplifier is designed only for a relatively low amplifier output and that an additional pressure increase is then carried out by a pressure increase unit, preferably a hydraulic pump.
• a variable representing the driver's brake request is used as the guide variable for the additional pressure increase.
• the pedal travel of a brake pedal and / or a variable derived from the pedal travel, in particular a pedal speed or acceleration, is preferably used as a variable representing the driver's braking request.
• a modulation point of the hydraulic booster is determined on the basis of a ratio of the pressure in the hydraulic accumulator to the pressure in the master brake cylinder and a constructive ratio of the area of a hydraulic piston in the hydraulic booster to the area of a hydraulic piston in the master brake cylinder.
• a control of the brake pressure in the wheel brakes by switching two electronically controllable valves is provided in a closed hydraulic system in particular.
• the figure shows a braking system according to the invention.
• the brake pressure transmitter has a hydraulic booster (7) which is designed as an extension of the actuating unit (THZ) 11 with the container 13.
• the booster piston 41 is guided in an booster housing, a push rod 42 of the booster piston 41 being supported in the piston 51 of the push rod circuit of the THZ 11 or being guided through a corresponding disk-like enlargement of the diameter in the THZ bore (not shown).
• a control line 50 opens into a space 47, which lies behind the booster piston 41.
• a push rod 46 of the brake pedal 26 penetrates the amplifier 7, which enables the THZ 11 to be actuated in an emergency if the amplifier 7 should fail. This emergency operation corresponds to the emergency operation of a vacuum brake booster.
• booster piston 41 and THZ area in conjunction with the pressure made available by a high-pressure source, gives the THZ pressure to be achieved with reinforcement. It is envisaged to achieve a corresponding structural design of the surface conditions and / or to achieve the maximum requested pressure Design high-pressure accumulator for a corresponding maximum pressure to be stored.
• a hydraulic high-pressure accumulator is preferably used as the high-pressure source, which supplies a pressurized brake fluid, ie “charged 1 ”, by means of a hydraulic pump.
• a return pump already present in the system is advantageously used for charging a accumulator.
• the store is loaded after braking, for example when the hydraulic pressure in the store reaches less than 40 to 50 bar, which corresponds to a brake pressure (modulation pressure) of 80 to 90 bar.
• a charging time of approx. 2 to 3.5 seconds is required by the pump until an upper limit value for the hydraulic pressure in the accumulator from 50 to 70 bar, corresponding to an actuation pressure of 100 to 110 bar, is reached.
• the hydraulic accumulator empties completely, then the pump needs approx. 30 to 40 seconds to refill the hydraulic accumulator up to a hydraulic pressure of 50 to 70 bar.
• FIG. Shows a brake circuit (of a total of two brake circuits) connected to the actuation unit 11, which acts on two wheel brakes 30, 31.
• the structure and function of the second brake circuit for the two other wheel brakes is identical to the brake circuit shown and therefore need not be described in more detail.
• the brake circuits are acted upon by the master cylinder (THZ) 11, which is supplied with hydraulic fluid (hydraulic fluid) via a hydraulic reservoir 13.
• the master cylinder 11 is actuated via the hydraulic brake booster 7 described above.
• the pressure requested by the respective control or regulation of an electronic unit 28 is generated via the hydraulic amplifier 7 and the master cylinder 11.
• the wheel brakes 30, 31 are supplied with pressure by normally open (SO) valves 15.1 and 15.2 directly from the THZ 11 via a line 14, an SO isolating valve 9 and subsequent lines 14.1 and 14.2, the THZ 11 via the hydraulic amplifier 7 is actuated, which can be acted upon by a pressure source 4, 19, 20 with hydraulic pressure.
• SO normally open
• Brake pressure is reduced via a return line 17 and normally closed (SG) valves 16.1 and 16.2, a low-pressure accumulator 18 and the pump.
• SG normally closed
• the charge of a high-pressure accumulator 4 is carried out by the valve 2 which is open when de-energized.
• the pressure in the high-pressure accumulator is below one Predetermined setpoint, in particular below 50 bar to 70 bar, falls, brake fluid is sucked in from the THZ 11 via the open changeover valve 8 and by means of the pump 19 operated with the motor 20.
• the brake fluid is pumped into the high-pressure accumulator 4 via a check valve 23 connected to the pressure side 21 of the pump 19, a damping chamber 57, via a line branch 22 and a line 24 into which the valve 2 and a pressure sensor 3 are inserted.
• the motor 20 is controlled until a predetermined target pressure is reached.
• the pressure is measured by a pressure sensor (pressure sensor 3).
• valve 5 When filling the high-pressure accumulator 4 (accumulator charging), the valve 5 arranged in a line 50 between the high-pressure accumulator 4 and the amplifier 7 is closed.
• the pressure side of the pump is also connected to the wheel brakes 30, 31 via the branch 22 and an adjoining line 25, into which a valve 1 is inserted.
• Valve 1 is preferably closed when de-energized (SG valve) and valve 2 is open when de-energized (SO valve). Then these valves are not energized during the store charging, advantageously only the changeover valve 8 then being energized for filling.
• valves 1 and 2 By switching valves 1 and 2 during normal brake pressure control, as in the case of ABS or ESP control, control in a closed hydraulic system is possible. Media separation is thus ensured, which brings advantages in the event of a high-pressure accumulator which may gas out.
• the boost pressure of the high-pressure accumulator is designed depending on the design, the booster and the desired TH pressure.
• valve 1 as an SO valve and valve 2 as an SG valve, with the switching states then having to be reversed accordingly.
• the charging process is preferably carried out in phases in which the engine load of the drive motor or a variable representing the engine load, such as
• Throttle valve position and / or accelerator pedal position approximately constant or with an increasing gradient.
• a steeply decreasing gradient of the engine load interrupts the charging process.
• no charging process is carried out or ongoing charging processes are interrupted.
• charging processes of the high-pressure accumulator are permitted if no other control functions, e.g. a brake intervention of a higher-level control system, such as distance and follow-up control (ACC system), is engaged.
• a brake intervention of a higher-level control system such as distance and follow-up control (ACC system)
• the charging process of the high-pressure accumulator 4 is stopped immediately.
• the braking detection takes place via a pedal travel sensor 60 or by means of another sensor which detects the driver's braking request. If a braking request is detected by the sensor system 60, the valve 5, which is preferably to be operated in an analog manner, is opened accordingly depending on the travel path of the push rod 46 of the brake pedal 24 and / or the actuation speed, so that brake fluid from the charged high-pressure accumulator 4 into the space behind the booster piston 47 can flow.
• the build-up of the pressure in the amplifier 7 is monitored by the pressure in the THZ using a pressure sensor 10. This means that a certain path is assigned and regulated to a certain pressure in the THZ.
• the booster piston 41 moves in front of the push rod 46 of the brake pedal 26, which is increasingly penetrating into the booster chamber, without any contact being made or having to be made. It is preferably provided to provide an elastic means, in particular a spring, between the push rod 46 and the booster piston 41 in order to achieve an elastic coupling.
• valve 6 which is also preferably to be operated analogously, is opened in a line 12 between the high-pressure accumulator 4 and the container 13, corresponding to the withdrawal of the driver's request, and the Brake fluid can flow back into the reservoir 13.
• the valve 6 By preferably designing the valve 6 as an SO valve, it is possible to actuate the amplifier in the event of a system failure, without negative pressure being generated in the amplifier 4 (or in the amplifier chamber 47), because volume compensation takes place via the valve 6.
• the driver only has to overcome the additional force which is generated by the pressure already set in the booster 7. This Additional force is only dependent on the surface of the push rod 46 that penetrates into the amplifier 7.
• the method according to the invention and the combination of the hydraulic booster and the auxiliary pressure source with high-pressure accumulator 4 can be designed such that the entire required brake pressure is generated by the booster. However, this increases the required storage pressure in the high-pressure accumulator 4.
• Control pressure to provide (similar to a vacuum brake booster). This already covers a large area of all braking operations, e.g. all "normal braking” in a range from a maximum of up to 60 to 80 bar resulting brake pressure, from the braking, which is a brake pressure above this control point
• the modulation point is determined by the ratio of accumulator pressure to THZ pressure and the ratio of booster piston area to THZ piston area.
• the described method is advantageously suitable for electronic brake control systems, such as ABS (anti-lock braking system), EDS (electronic differential lock, traction control), ESP (electronic stability program), or HDC (hill descent control, downhill regulation). It can also be used for systems with distance and follow-up control (ACC, Adaptive Cruise Control), since the THZ automatically balances the pressure in the circuits.
• ABS anti-lock braking system
• EDS electronic differential lock, traction control
• ESP electronic stability program
• HDC hill descent control, downhill regulation
• ACC Adaptive Cruise Control

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Transportation (AREA)
• Mechanical Engineering (AREA)
• Electromagnetism (AREA)
• Regulating Braking Force (AREA)
• Braking Systems And Boosters (AREA)

Applications Claiming Priority (3)

Publications (1)

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Family Applications (1)

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• 2003
  • 2003-11-13 US US10/534,532 patent/US20060091724A1/en not_active Abandoned
  • 2003-11-13 JP JP2004552722A patent/JP2006506269A/ja not_active Withdrawn
  • 2003-11-13 DE DE10393699T patent/DE10393699D2/de not_active Expired - Lifetime
  • 2003-11-13 WO PCT/EP2003/050827 patent/WO2004045934A2/de not_active Application Discontinuation
  • 2003-11-13 EP EP03796018A patent/EP1565364A2/de not_active Withdrawn

Non-Patent Citations (1)

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