Patent Application
20110060510
1. Field of the Invention
The present disclosure relates to systems and methods for increasing brake pressure using one or more pyrotechnic devices.
2. Background Art
A vehicle may be provided with an emergency brake intervention system that automatically builds up brake pressure in the event that a potential collision situation is detected. Such a system may detect a rapid closing of the vehicle on an obstacle using a radar system or other vision or laser rangefinder device. In the event that a collision situation is detected, brake pressure may be built up automatically by a vacuum brake booster or a pump of an antilock braking system.
According to an embodiment of the present disclosure, a vehicle brake system may be provided with a brake unit, a brake line associated with the brake unit, and an activatable pyrotechnic device associated with the brake line. Upon activation, the pyrotechnic device is configured to supply gas directly into the brake line to increase pressure in the brake line, such that increased pressure is applied to the brake unit.
A method of increasing braking pressure in a vehicle brake system that includes a brake unit and a brake line associated with the brake unit is also provided. The method includes detecting a potential collision event, and activating a pyrotechnic device in response to detection of the potential collision event, such that gas is supplied directly into the brake line to increase pressure applied to the brake unit.
While exemplary embodiments in accordance with the invention are illustrated and disclosed, such disclosure should not be construed to limit the claims. It is anticipated that various modifications and alternative designs may be made without departing from the scope of the invention.
The brake system 12 may include one or more brake units 14 that are each associated with a particular wheel 16, or other motion device, of the vehicle 100. In the embodiment shown in
The brake units 14 are connected to one or more brake pumps, such as a master cylinder 18, by one or more brake lines 20, such as tubes and/or hoses, that contain a suitable brake fluid, such as hydraulic oil. The master cylinder 18 is configured to increase pressure in the brake lines 20 in response to a vehicle operator depressing a brake pedal 22, which is operatively connected to or otherwise associated with the master cylinder 18. For example, the brake pedal 22 may be connected directly or indirectly to a plunger or piston 24 of the master cylinder 18, such that downward and/or forward movement of the brake pedal 22 may cause movement of the piston 24 from an initial position to a brake-actuate position. As a result, the master cylinder 18 forces brake fluid through the brake lines 20, thereby applying increased pressure at the brake units 14, which causes the brake units 14 to apply braking force on the wheels 16.
In the embodiment shown in
The master cylinder 18 may also be in fluid communication with a reservoir 25 that contains additional brake fluid. The master cylinder 18 may draw brake fluid from the reservoir 25 as needed to sufficiently increase pressure in the brake lines 20.
The brake system 12 further includes one or more pyrotechnic devices, such as pyrotechnic charges or cartridges, associated with one or more of the brake lines 20 for rapidly increasing pressure in the one or more brake lines 20. Each pyrotechnic device may be any suitable device, such as a gas generator used in air bag system or seat belt pretensioner for example. In the embodiment shown in
The pyrotechnic device 26 is configured to increase pressure in the brake line 20f as explained below in detail. Furthermore, the pyrotechnic device 26 may increase pressure in the brake line 20f to any suitable level, such as a pressure in the range of about 100 to 120 bar.
In another embodiment, an additional pyrotechnic device 26 may be connected to the brake line 20r. In yet another embodiment, a brake system according to the present disclosure may include a single pyrotechnic device 26 connected to the brake line 20r, and no pyrotechnic device connected to the brake line 20f.
The brake system 12 shown in
The CDS 32 may be positioned at or near a front portion of the vehicle 10, and may have any suitable components for sensing or otherwise detecting a potential collision event. For example, the CDS 32 may include a radar system and/or a laser system for detecting an obstacle or target in the path of the vehicle 10 or approaching the vehicle 10. Alternatively or supplementally, the CDS 32 may include one or more sensors that sense a vehicle parameter that may be indicative of a potential collision event. For example, the CDS 32 may include an accelerometer 36 that is configured to detect sudden changes in vehicle acceleration.
The ABS modulator 34 is configured to control or regulate pressure in the brake lines 20 to inhibit or prevent lock up of any of the wheels 16 during braking events. In the embodiment shown in
Referring to
With the above configuration, the pyrotechnic device 26 supplies gas directly into the brake line 20f such that the gas contacts the brake fluid. The gas may subsequently be bled out from the brake line or lines 20 through one or more bleed ports 38, such that the brake system 12 may be returned to normal operation.
With such a configuration, in response to detection of a potential collision event by the CDS 32, the controller 30 may be used to control operation of the pyrotechnic devices 26 to automatically apply braking force on all wheels 16 or reinforce braking action of the vehicle operator. As another example, the controller 30 may activate only one of the pyrotechnic devices 26 in response to detection of a potential collision event.
With such a configuration, in response to detection of a potential collision event by the CDS 32, the controller 30 may activate all of the pyrotechnic devices 26 to automatically apply braking force on all wheels 16, or reinforce braking action of the vehicle operator. As another example, the controller 30 may selectively activate one or more of the pyrotechnic devices 26 in response to detection of a potential collision event. For instance, one or both pyrotechnic devices 26 on one side of the vehicle 10″ may be activated to introduce a yaw moment on the vehicle 10″ to cause the vehicle 10″ to turn toward or away from an obstacle. As a result, the direction of the vehicle 10″ may be adjusted or altered to optimize protection afforded by other safety features, such as safety devices or crumple zones, of the vehicle 10″. For example, if the vehicle 10″ is provided with a front crumple zone to dissipate energy, the pyrotechnic devices 26 may be selectively activated to cause the vehicle 10″ to turn toward an obstacle such that the front crumple zone contacts the obstacle. More generally, the pyrotechnic devices 26 may be selectively activated to cause the vehicle 10″ to turn such that collision energy transferred to a vehicle occupant may be minimized.
It should be noted that the brake lines 20 in the embodiment shown in
While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.
