This application is the U.S. national phase application of PCT International Application No. PCT/EP2007/055025, filed May 23, 2007, which claims priority to German Patent Application No. DE102007005459.0, filed Feb. 3, 2007, the contents of such applications being incorporated by reference herein.
1. Field of the Invention
The invention relates to a brake booster for a motor vehicle brake system of the brake-by-wire type, which can be activated both by means of a brake pedal and as a function of a driver's request, as well as independently of the driver's wish by means of an electronic control unit, wherein the coupling of the brake pedal, or of a force transmitting part which is permanently connected to the brake pedal, to an input member of the brake booster is embodied in such a way that the brake pedal or the force transmitting part which is permanently connected to the brake pedal can carry out a limited relative movement with respect to the input member, which ensures, in particular in the brake-by-wire operating mode, a decoupling of the force transmitting connection between the brake pedal or the force transmitting part which is permanently connected to the brake pedal.
2. Description of the Related Art
A brake booster is known from European patent EP 0 417 945 B1. A piston rod which forms the input member of the previously known brake booster has a longitudinal opening which holds a bolt which is permanently connected to a brake pedal. The longitudinal opening permits a limited relative movement of the input member with respect to the bolt or the brake pedal with the result that when the brake booster is used in a case of drive slip control or when the brake booster is actuated independently of the driver's wish, the input member moves in the direction of activation while the brake pedal remains stationary. The large amount of friction which occurs between the input member and the bolt causes a large amount of wear of said parts, causes them to corrode and generates noise which is felt to be unpleasant and disruptive by the driver of the vehicle.
An object of one or more aspects of the present invention is to improve a brake booster of the generic type mentioned at the beginning to the effect that the disadvantages specified above are very largely avoided.
In accordance with at least one aspect of the invention, the force transmitting part, which is permanently connected to the brake pedal, and/or the input member of the brake booster are/is provided in the region of the relative movement of the two parts with respect to one another with means which reduce friction which occurs during the relative movement of the parts with respect to one another.
Further features and advantages of the invention emerge from the following description of exemplary embodiments with reference to the appended drawing, in which:
a, b show a side view or a front view of a first embodiment of the subject matter of at least one aspect of the invention;
a, b show a side view or a front view of a second embodiment of the subject matter according to at least one aspect of the invention;
a, b show a side view or a plan view of a third embodiment of the subject matter according to at least one aspect of the invention;
a, b show a side view or a front view of a fifth embodiment of the subject matter according to at least one aspect of the invention;
a, b show three-dimensional illustrations of a sixth embodiment of the subject matter according to at least one aspect of the invention;
a, 8b and 8c show two three-dimensional illustrations and an illustration of a detail of sliding shoes of a seventh embodiment of the subject matter according to at least one aspect of the invention;
a, 9b and 9c show two three-dimensional illustrations and an exploded illustration of a sliding shoe, of a damping element and of a securing part of an eighth embodiment of the subject matter according to at least one aspect of the invention;
a, 11b and 11c show a three-dimensional illustration, a plan view and an illustration of a detail of sliding blocks of a tenth embodiment of the subject matter according to at least one aspect of the invention.
The activation unit illustrated in
An input member which is coupled to the brake pedal 4, or a piston rod 7 which is used by the driver to activate the control valve mentioned above, has a piston rod head 8 in which a longitudinal opening 9 is formed. The longitudinal opening 9 holds a force transmitting part 10 which is connected to the brake pedal 4 and which is embodied as a bolt. In this context, the abovementioned parts 8, 10 are arranged in such a way that an axial gap or distance “a” which ensures decoupling of the force transmitting connection between the brake pedal 4 and the brake booster 1 in the brake-by-wire operating mode, is provided between the boundary of the longitudinal opening 9 which is on the left in the drawing and the bolt 10. An axial gap or distance “b” which is provided between the bolt 10 and the boundary of the longitudinal opening 9 which is on the left in the drawing prevents the brake pedal 4 from also being moved along when the brake booster 1 is actuated independently of the driver's wish. A travel sensor 11 is used to sense the travel of a movable wall which applies the boosting force of the brake booster 1, or the travel of an output member of the brake booster 1 which transmits its output force to a first piston (not illustrated) of the master brake cylinder 2.
The pedal travel simulator 5 by means of which, as already mentioned, a restoring force which acts on the brake pedal 4 can be simulated in the brake-by-wire operating mode independently of activation of the brake booster 1 is embodied in such a way that in the brake-by-wire operating mode it can be activated during the decoupling of the force transmitting connection between the brake pedal 4 and the brake booster 1 and deactivated outside the brake-by-wire operating mode by means of an activation and deactivation device 12, which is only indicated schematically.
In the first example (illustrated in
In the embodiments of the invention illustrated in
In the further embodiments (illustrated in
In the further variant shown in
In the embodiment illustrated in
In the exemplary embodiment shown in
The design of the ninth exemplary embodiment of the subject matter of at least one aspect of the invention which is illustrated in
Finally, in the tenth embodiment shown in
Number | Date | Country | Kind |
---|---|---|---|
10 2007 005 459 | Feb 2007 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/EP2007/055025 | 5/23/2007 | WO | 00 | 1/19/2010 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2008/095546 | 8/14/2008 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5350225 | Steiner et al. | Sep 1994 | A |
6152642 | Berthold et al. | Nov 2000 | A |
6609438 | Bigham et al. | Aug 2003 | B1 |
6758115 | Allen et al. | Jul 2004 | B2 |
7568406 | Booher et al. | Aug 2009 | B2 |
20080196983 | Von Hayn et al. | Aug 2008 | A1 |
20090115247 | Leiber et al. | May 2009 | A1 |
Number | Date | Country |
---|---|---|
42 08 496 | Aug 1993 | DE |
10 2004 011 622 | Mar 2005 | DE |
20 2005 018 018 | Oct 2006 | DE |
0 417 945 | Mar 1991 | EP |
WO 2005014351 | Feb 2005 | WO |
WO 2006111393 | Oct 2006 | WO |
Number | Date | Country | |
---|---|---|---|
20100164277 A1 | Jul 2010 | US |