Electronically slip-controllable power-assisted braking system, in particular for a motor vehicle

Patent metadata

Field	Value
Publication number	US-10399546-B2
Application number	US-201615187501-A
Country	US
Kind code	B2
Filing date	Jun 20, 2016
Priority date	Jun 22, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

An electronically slip-controllable power-assisted braking system for a motor vehicle. The power-assisted braking system is equipped with a hydraulically acting booster device that is inserted in a brake circuit downstream from an actuation device and has a piston unit movably guided in a cylinder housing. The piston unit is embodied in stepped fashion and divides an interior space of the cylinder housing into multiple booster chambers impinged upon by pressure medium. At least one of these booster chambers is capable of being impinged upon by pump pressure from a pump driven by external force.

First claim

What is claimed is:

1. An electronically slip-controllable power-assisted braking system for a motor vehicle, comprising:
an actuation device capable of being impinged upon by muscle force;
a booster device configured to interact with the actuation device for generation of a circuit pressure in at least one brake circuit connected to the actuation device;
a pressure modulation device capable of having control applied electronically to it and provided in the brake circuit, for converting the circuit pressure into a brake pressure as a function of slip conditions existing at a wheel of a vehicle equipped with the power-assisted braking system; and
at least one wheel brake connected to the brake circuit, the at least one wheel brake being associated with the wheel of the vehicle and converting the brake pressure into a wheel braking force;
wherein:
the booster device is arranged in the brake circuit downstream from the actuation device;
the booster device includes:
(a) a cylinder housing that defines an interior space within the cylinder housing; and
(b) a piston unit that is guidable movably within the interior space of the cylinder housing and that divides the interior space into a plurality of booster chambers sealed from each other;

the plurality of booster chambers includes a first booster chamber that is connected to a discharge side of a pump that is drivable by external power for obtaining from the pump a pressure medium under discharge pressure of the pump; and
at least one of:
the plurality of booster chambers includes a second booster chamber that is fluidically connected to a suction side of the pump for obtaining from a line in which the pump is arranged pressure medium that is under suction pressure of the pump;
the plurality of booster chambers includes a third booster chamber (a) that is located beyond a first longitudinal end face of the piston unit so that the first longitudinal end face of the piston unit is a wall of the third booster chamber and (b) that is perpetually fluidically sealed within the cylinder housing from the first booster chamber and from which pressure medium is suppliable from the interior space of the booster device to the at least one wheel brake, with the first booster chamber, when connected to the discharge side of the pump, being entirely formed around, and radially exterior to, a mid-section of the piston unit that is between the first longitudinal end face of the piston unit and a second longitudinal end face of the piston unit, which is opposite the first longitudinal end face;
the plurality of booster chambers includes at least three chambers that are each perpetually fluidically sealed within the cylinder housing from each of the others of the at least three chambers, the piston device including a piston element that divides the interior space into the at least three chambers and that is movable only in its entirety; and
the pump is arranged in a return line so that pressure medium is returnable, via the pump, from the at least one wheel brake to a pressure medium reservoir for feeding of pressure medium from the at least one wheel brake.

2. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein the plurality of booster chambers includes a fourth booster chamber that is connected to the actuation device of the power-assisted braking system, and the plurality of booster chambers includes the third booster chamber, which is contacted to the pressure modulation device.

3. The electronically slip-controllable power-assisted braking system as recited in claim 2 , wherein the plurality of booster chambers includes the second booster chamber, the first booster chamber is located opposite the second booster chamber, and the fourth booster chamber is connected located opposite the third booster chamber.

4. The electronically slip-controllable power-assisted braking system as recited in claim 2 , wherein the pressure in the third booster chamber is variably adjustable via an adaptation of the pressure impingement upon the fourth booster chamber and upon the first booster chamber.

5. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein the piston unit is constructed from at least two mutually interacting piston components having outside diameters of different sizes, the piston components being disposed movably relative to one another in the interior space of the cylinder housing.

6. The electronically slip-controllable power-assisted braking system as recited in claim 5 , wherein the piston components respectively separate two mutually oppositely located booster chambers of the booster unit from one another.

7. The electronically slip-controllable power-assisted braking system as recited in claim 5 , wherein the piston components are mechanically couplable in order to transfer a pressure force from one of the piston components to the respective other one of the piston components.

8. The electronically slip-controllable power-assisted braking system as recited in claim 5 , wherein one of the piston components is a cylindrical piston and another of the piston components is an annular piston, an entraining element for the annular piston being embodied on the cylindrical piston.

9. The electronically slip-controllable power-assisted braking system as recited in claim 8 , wherein the entraining element is embodied in the form of a collar protruding radially from the cylindrical piston.

10. The electronically slip-controllable power-assisted braking system as recited in claim 5 , wherein one of the piston components is slidable within another of the piston components.

11. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein a throttled pressure medium connection, which is controllable by an outflow valve capable of having electronic control applied to it, exists between the discharge side and the suction side of the pump.

12. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein the plurality of booster chambers includes the second booster chamber that is fluidically connected to the suction side of the pump for obtaining from the line in which the pump is arranged pressure medium that is under suction pressure of the pump.

13. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein the plurality of booster chambers includes the third booster chamber (a) that is located beyond the first longitudinal end face of the piston unit so that the first longitudinal end face of the piston unit is the wall of the third booster chamber and (b) that is perpetually fluidically sealed from the first booster chamber and from which pressure medium is suppliable from the interior space of the booster device to the at least one wheel brake, with the first booster chamber being formed around, and radially exterior to, a mid-section of the piston unit that is between the first longitudinal end face of the piston unit and a second longitudinal end face of the piston unit, which is opposite the first longitudinal end face.

14. The electronically slip-controllable power-assisted braking system as recited in claim 1 , wherein the plurality of booster chambers includes the at least three chambers that are each perpetually fluidically sealed within the cylinder housing from each of the others of the at least three chambers, the piston device including the piston element that divides the interior space into the at least three chambers and that is movable only in its entirety.

15. The electro

Assignees

• Bosch Gmbh Robert

Inventors

• Drotleff Dirk

Classifications

• B60T15/24

  controlled by three fluid pressures · CPC title

• B60T13/686

  in hydraulic systems or parts thereof · CPC title

• B60T13/662

  characterised by specified functions of the control system components · CPC title

• B60T13/166

  Part of the system directly actuated by booster pressure · CPC title

• B60T8/445

  replenishing the released brake fluid volume into the brake piping · CPC title