Pressure build-up controlled brake system with specific interconnection of inlet valves with brake circuit/wheel brakes and method for controlling pressure

Patent metadata

Field	Value
Publication number	US-11584348-B2
Application number	US-201515558438-A
Country	US
Kind code	B2
Filing date	Dec 30, 2015
Priority date	Mar 16, 2015
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

An operating device for a vehicle brake system may include a control device and a piston-cylinder unit, at least one chamber of which may be connected to at least one wheel brake via at least one hydraulic line and a valve device that has at least normally open inlet valves or switching valves. The device may further include a pressure source that may be controlled to supply pressure medium to the at least one hydraulic line or to the at least one wheel brake. The control device may control pressure build-up via volume control and/or time control, using inlet valves. The interior or armature chamber of an inlet valve may be connected to a corresponding brake circuit via a hydraulic line, and a valve seat outlet may be connected to a corresponding wheel brake via a hydraulic line.

First claim

What is claimed is:

1. An operating device for a vehicle brake system, the operating device including:
a control device,
two or more wheel brakes,
brake circuits,
a first piston cylinder unit, at least one working chamber of which is connected to at least one of the two or more wheel brakes via at least one first hydraulic line and a valve device that has at least normally open 2/2-way inlet valves and at least one outlet valve, and
a pressure source enabled to be controlled to supply a pressure medium to the at least one hydraulic line or to the at least one of the two or more wheel brakes connected to the at least one hydraulic line,
wherein the control device is configured to control pressure build-up via the inlet valves, wherein pressure build-up by the first piston cylinder unit and the pressure source in a respective one of the at least one of the two or more wheel brakes is performed via a respective one of the 2/2-way inlet valves, and wherein the control device is further configured to set or adjust respective pre-pressures at the two or more wheel brakes to respective levels based at least in part on respective coefficients of road friction at the two or more wheel brakes,
wherein an interior or armature chamber of the respective one of the 2/2-way inlet valves is connected to a corresponding one of the brake circuits via a second hydraulic line,
wherein a valve seat outlet of the respective one of the 2/2-way inlet valves is connected to the respective one of the at least one of the two or more wheel brakes via a third hydraulic line,
wherein pressure reduction in the respective one of the at least one of the two or more wheel brakes takes place via the respective one of the 2/2-way inlet valves associated with the respective one of the at least one of the at least one of the two or more wheel brakes, wherein the respective one of the 2/2-way inlet valves has only one valve seat and one plunger, whereby a magnetic armature moves the plunger so that the plunger comes up against the valve seat to close the valve seat outlet, and
wherein pressure build-up in the respective one of the at least one of the two or more wheel brakes takes place by means of a volume control as specified by the control device, wherein the pressure source is configured to adjust or provide a displacement volume of hydraulic medium to achieve a desired pressure change, and/or by means of time-controlled inlet valve opening simultaneously, with a time overlap, or one after the other, wherein the control device, for a complete pressure change in the respective wheel brake, is configured to open the respective one of the 2/2-way inlet valves at the start of a determined time period and to close the respective one of the 2/2-way inlet valves after the time period has elapsed.

2. The operating device according to claim 1 , wherein in certain control situations due to different coefficients of road friction at the various ones of the two or more wheel brakes, where there is a pressure build-up in at least two of the two or more wheel brakes, the respective target pressures of which are at different levels, the control device, by means of the pressure source is configured to set or adjust the respective pre-pressures of the at least two of the two or more wheel brakes, wherein the pre-pressure for one of the at least two of the two or more wheel brakes is set or adjusted to a lower level than an actual pressure of at least one other wheel brake of the at least two of the two or more wheel brakes.

3. The operating device according to claim 1 , wherein a return spring is configured to apply a force to a valve actuator in a direction of an opened position of the respective one of the 2/2-way inlet valves.

4. The operating device according to claim 3 , wherein wheel brake pressure supports opening of the respective one of the 2/2-way inlet valves, in the event of failure of the supply voltage, wherein the respective one of the 2/2-way inlet valves is pushed open by the wheel brake pressure and the return spring.

5. The operating device according to claim 3 , wherein the inlet valves are normally open valves, wherein hydraulic medium under pressure in the wheel brake associated with the respective one of the 2/2-way inlet valves applies a force to a movably mounted valve member disposed at the valve seat, which, in case of an emergency or in the event of a failure of the control device or the power supply, moves the valve member away from the valve seat and opens the respective one of the 2/2-way inlet valves.

6. The operating device according to claim 2 , wherein the pre-pressure associated with the at least one of the at least two of the two or more wheel brakes supports a closing process of at least one of the 2/2-way inlet valve that is associated with the at least one of the at least two of the two or more wheel brakes.

7. The operating device according to claim 1 , wherein the valve seat of the respective one of the 2/2-way inlet valves is a pressure-relieved valve seat or wherein the respective one of the 2/2-way inlet valves is designed with a corresponding return spring, which ensures that the respective one of the 2/2-way inlet valves is opened at maximum brake pressure in a corresponding wheel brake of the at least two wheel brakes.

8. The operating device according to claim 1 , wherein a combination of volume control and timing control is provided for, wherein the volume control takes place by volume delivery and the timing control takes place according to a pressure differential between a wheel pressure and a pre-pressure corresponding to a wheel associated with the wheel pressure.

9. The operating device according to claim 1 , wherein a time-variable control pre-pressure level for pressure changes is enabled to be set or adjusted by means of the pressure source, wherein a pre-pressure differential, defined as a difference between the pre-pressure and an actual pressure, for a particular one of the at least two wheel brakes undergoing pressure change, has a value less than or equal to 40 bar, and wherein a corresponding pressure differential between the control pre-pressure level and a wheel target pressure of a particular wheel is maintained at between 10 and 20 bar.

10. The operating device according to claim 1 , wherein a pressure supply to the two or more wheel brakes takes place with a single circuit, wherein a working chamber of the pressure source that is able to be controlled is connected via isolation valves with the brake circuits.

11. The operating device according to claim 1 , wherein the pressure source comprises at least one piston, differential piston, double-stroke piston or delivery pump, connected directly or via hydraulic elements with the reservoir.

12. The operating device according to claim 1 , wherein volume control takes place in a variable manner over time.

13. The operating device according to claim 1 , wherein the operating device further includes a brake pedal device, for the first piston cylinder unit.

14. A method of operating the operating device according to claim 1 , the method comprising: maintaining a control pre-pressure of the pressure source at an actual wheel brake pressure in control mode at a level less than or equal to 150 bar.

15. The method according to claim 14 , wherein the method further includes, in a multiplex case, releasing, under at least one fault condition, pressure contained at the at least one of the two or more wheel brakes using valves of the valve device without using additional non-return valves.

16. The method according to claim 14 , further including dynamical

Assignees

• Ipgate Ag

Inventors

• Leiber Heinz
• Leiber Thomas
• Van Zanten Anton

Classifications

• B60T8/4086

  the stroke simulating device being connected to, or integrated in the driver input device · CPC title

• B60T13/745 Primary

  acting on a hydraulic system, e.g. a master cylinder · CPC title

• B60Y2400/81

  Braking systems · CPC title

• B60T7/042 Primary

  by electrical means, e.g. using travel or force sensors · CPC title

• B60Y2400/306

  Pressure sensors · CPC title