Motors: expansible chamber type – Working member position feedback to motive fluid control – Follower type
Patent
1997-11-17
2000-02-08
Nguyen, Hoang
Motors: expansible chamber type
Working member position feedback to motive fluid control
Follower type
91376R, F15B 910
Patent
active
060217049
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a brake power booster including an actuating rod which is in force-transmitting connection with an actuating pedal, and a device for determining an input force, applied to the actuating pedal, which has a pressure chamber that interacts with a pressure generator and is filled with an elastic substance.
A brake power booster disclosed in German Patent No. 42 08 496 includes a device for determining the actuating force introduced at the brake pedal. The device includes force sensors configured as resistance strain gauges or load cells arranged at the brake pedal which can be realized by pressure-responsive resistors or piezoelectric materials. This means that the pedal force is sensed outside the booster housing. Both sensor types must be calibrated individually. This makes them inappropriate for application in large-series production for cost reasons.
In another brake power booster disclosed in German patent application No. 36 27 279, the actuating force introduced at the brake pedal is determined by way of the pressure which develops in an elastic part upon actuation. For this purpose, there is provision of a piston which bears against the elastic part and is displaceable axially within limits. The piston interacts with a pressure sensor which issues signals proportional to the magnitude of the input force. In order to protect the pressure sensor against damage when very high pedal forces prevail, the pressure sensor is so arranged as to be slidable within limits in an axial direction, counteracting the effect of a compression spring, in opposition to the actuating direction of the brake power booster. A disadvantage in the prior art brake power booster is that, for realization of the principle of determining the input force illustrated, extensive constructive modifications are required in the area of the force transmission between the actuating rod and an output force delivering member. These modifications necessitate considerable effort and structure.
Therefore, an object of the present invention is to disclose arrangements which permit sensing the input force introduced at the actuating pedal without constructive modifications to the force transmission area inside the booster housing. The sensing operation shall be effected at low cost and without necessitating large mounting space.
SUMMARY OF THE INVENTION
In a first solution of this objective, the pressure chamber filled with the elastic substance and the pressure generator are arranged between two telescopically slidable parts of the actuating rod having a bipartite design.
A second solution of the above mentioned objective in a brake power booster, having an actuating rod which interacts with a valve piston of a control valve, includes that the device for determining the input force is arranged in the valve piston and that the transmission of forces from the actuating rod to the elastic substance is effected by way of a pressure member which defines the pressure chamber axially.
A third solution of the objective to be achieved by the present invention includes that the device for determining the input force is a force generator which is arranged in the valve piston coaxially to the actuating rod. Preferably, forces are transmitted from the actuating rod to the force generator by way of an intermediate piece.
The present invention will be explained in detail in the following description of four embodiments, making reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings,
FIGS. 1-3 are views of a first, second and third embodiment of the subject matter of the present invention.
FIG. 4 is a fourth embodiment of the subject matter of the present invention operating according to a different principle.
FIG. 5 is a fifth embodiment of the subject matter of the present invention operating according to the principle of FIGS. 1 to 3.
DETAILED DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an actuating rod 1 of a pneumatic brake power booster (not shown) which is
REFERENCES:
patent: 5293808 (1994-03-01), Rueffer et al.
patent: 5487325 (1996-01-01), Bayliss et al.
patent: 5605088 (1997-02-01), Balz et al.
patent: 5647462 (1997-07-01), Tsubouchi et al.
patent: 5845556 (1998-12-01), Tsubouchi et al.
Patent Abstracts of Japan, vol. 8, no.253 (M-339),11-20-84.
Patent Abstracts of Japan, vol. 9, no.46 (M-360),10-23-84.
Berthold Thomas
Drumm Stefan
Eckert Alfred
ITT Manufacturing Enterprises Inc.
Nguyen Hoang
LandOfFree
Braking force amplifier does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Braking force amplifier, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Braking force amplifier will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1673234