Pressure transmission device for a vehicle, power-assisted braking system and method

Patent metadata

Field	Value
Publication number	US-9403515-B2
Application number	US-201113977292-A
Country	US
Kind code	B2
Filing date	Oct 28, 2011
Priority date	Dec 28, 2010
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A pressure transmission device for a power-assisted braking system of a vehicle; at its inlet, the pressure transmission device being connectible in a hydraulically operative manner to a master brake cylinder of the power-assisted braking system, and at its outlet, the pressure transmission device being connectible in a hydraulically operative manner to a wheel brake cylinder of the power-assisted braking system; the pressure transmission device including an accumulator and a linkage, which transmits a pressure difference between the inlet and the outlet to the accumulator and stores it in this.

First claim

What is claimed is:

1. A pressure transmission device for a power-assisted braking system of a vehicle, comprising:
an inlet, the inlet of the pressure transmission device being connectible in a hydraulically operative manner to a master brake cylinder of the power-assisted braking system;
an outlet, the outlet of the pressure transmission device being connectible in a hydraulically operative manner to at least one wheel brake cylinder of the power-assisted braking system;
an accumulator; and
a linkage, wherein the linkage transmits a pressure difference between the inlet and the outlet to the accumulator, and stores the pressure difference in the accumulator;
wherein at least one of: i) the inlet has a first cylinder having a first piston which is guided in the first cylinder and is movable in a first displacement direction, and to which a first pressure is applied, and ii) the outlet has a second cylinder having a second piston, which is guided in the second cylinder and is movable in a second displacement direction, and at which a second pressure is present, and
wherein the linkage has a stationary adjusting spindle running perpendicularly to the first displacement direction of the first piston and at least one transmission rod, which is supported at the adjusting spindle and is moveable in the first displacement direction by the first piston and is movable in an axial direction of the adjusting spindle.

2. The pressure transmission device as recited in claim 1 , wherein the transmission rod is operatively connected to a rocker arm, which is pivoted at an actuating section of the accumulator on its one end and is pivoted at the second piston on its other end.

3. The pressure transmission device as recited in claim 2 , wherein two transmission rods are provided, which, in a first adjustment position of the same, are situated on a center line that is coaxial with the first and second displacement directions of the first and second pistons and, in a second adjustment position, are symmetrically set apart from the center line; in the first adjustment position, the two transmission rods act upon the second piston via one of pivot points or a common pivot point of their respectively assigned rocker arms; and in the second adjustment position, the two transmission rods act upon the actuation section of the accumulator via pivot points of their respectively assigned rocker arms.

4. The pressure transmission device as recited in claim 2 , wherein the accumulator is a stored-energy spring mechanism, and the actuation section is formed by a jar, the jar accommodating a spring, and the jar is moveable along the center line, in order to actuate the spring and, consequently, charge the accumulator.

5. The pressure transmission device as recited in claim 1 , further comprising:
a driving device for moving the transmission rod in the axial direction of the adjusting spindle.

6. The pressure transmission device as recited in claim 5 , wherein the driving device is an electric motor.

7. The pressure transmission device as recited in claim 1 , wherein the adjusting spindle is a threaded spindle, on which the transmission rod is supported.

8. A method for controlling a pressure transmission device, for a power-assisted braking system of a vehicle, the device including a master brake cylinder, a wheel brake cylinder to brake a wheel of the vehicle, a pressure transmission device having an inlet connected in a hydraulically operative manner to the master brake cylinder, an outlet connected in a hydraulically operative manner to the wheel brake cylinder, an accumulator, and a linkage, the method comprising:
transmitting, via the linkage, a pressure difference between the inlet and the outlet to the accumulator and stores the pressure difference in the accumulator; and
adjusting, via a control device, a pressure transmitted by the pressure transmission device between the inlet and the outlet during recuperative braking of the wheel;
wherein the transmitted pressure is adjusted so that in the case of a pressure change at the outlet of the pressure transmission device resulting from recuperative braking of a wheel, a reaction force exerted on the driver of the vehicle at a brake pedal remains constant.

9. The method as recited in claim 8 , wherein in the case of braking the wheel without recuperation, at least one transmission element of the pressure transmission device is in a first adjustment position along a center line, and a pressure built up by the brake pedal and a master brake cylinder is transmitted to a piston assigned to the inlet of the pressure transmission device, and transmitted along the center line, through the at least one transmission element, to a piston, which is assigned to the outlet and pressurizes a wheel brake cylinder of the wheel.

10. The method as recited in claim 9 , wherein when a switchover is made from braking without recuperation to recuperative braking, the at least one transmission element is moved along an adjusting spindle of the linkage, from a first adjustment position into a second adjustment position set apart from the center line; and an actuation energy for actuating the wheel brake cylinder is transferred at least partially from the wheel brake cylinder into the accumulator.

11. The method as recited in claim 10 , wherein when a switchover is made from recuperative braking to braking without recuperation, the at least one transmission element is moved from the second adjustment position into the first adjustment position, a movement of the piston assigned to the inlet being monitored, and when a movement of the piston is detected, the moving of the at least one transmission element from the second adjustment position into the first adjustment position is one of slowed down or stopped, in order to adjust a reaction force at the brake pedal.

12. The method as recited in claim 11 , wherein the reaction force at the brake pedal is kept constant.

13. A power-assisted braking system for a vehicle, comprising:
a master brake cylinder;
a wheel brake cylinder to brake a wheel of the vehicle;
a pressure transmission device having an inlet connected in a hydraulically operative manner to the master brake cylinder, an outlet connected in a hydraulically operative manner to the wheel brake cylinder, an accumulator, and a linkage, wherein (i) in a first adjustment position, the linkage is configured to transmit a pressure at the inlet to the wheel brake cylinder and (ii) in a second adjustment position, the linkage is configured to transmit a pressure difference between the inlet and the outlet to the accumulator, and to store the pressure difference in the accumulator; and
a control device which adjusts a pressure transmitted by the pressure transmission device between the inlet and the outlet during recuperative braking of the wheel,
wherein at least one of: i) the inlet has a first cylinder having a first piston which is guided in the first cylinder and is movable in a first displacement direction, and to which a first pressure is applied, and ii) the outlet has a second cylinder having a second piston, which is guided in the second cylinder and is movable in a second displacement direction, and at which a second pressure is present, and
wherein the linkage has a stationary adjusting spindle running perpendicularly to the first displacement direction of the first piston and at least one transmission rod.

14. The braking system as recited in claim 13 , wherein the outlet of the pressure transmission device is one of: i) connected to a tank by a breather line or ii) connected to the inlet of the pressure transmission device

Assignees

• Mayer Jochen
• Bosch Gmbh Robert

Inventors

• Mayer Jochen

Classifications

• B60T13/586

  the retarders being of the electric type · CPC title

• B60T8/4266 Primary

  having an electro-mechanically actuated expansion unit, e.g. solenoid, electric motor, piezo stack · CPC title

• B60T8/489

  using separate traction control modulators · CPC title

• B60T13/14 Primary

  using accumulators or reservoirs {fed by pumps} · CPC title

• B60T8/441

  using hydraulic boosters (B60T8/445, B60T8/446, B60T8/447 take precedence) · CPC title