Bremsdruckregler fuer Fahrzeuge mit hydraulischer Bremseinrichtung

摘要

1,002,610. Fluid-pressure brakes. KELSEYHAYES CO. Dec. 11, 1962 [Dec. 18, 1961], No. 46809/62. Heading F2F. A device for progressively modifying the ratio between front and rear braking pressures in an hydraulic braking system of a vehicle, to compensate for the weight transfer during deceleration of the vehicle, comprises a differential piston operating in a bore within a housing of the device, a passage through the piston for direct transmission of fluid during initial application of the brake, a piston-like element movable relative to the piston and comprising a valve seat arranged so that the flow of fluid through the passage is blocked upon closure of the valve seat, a deceleration-responsive element adapted to close the valve seat at a predetermined rate of vehicle deceleration, and spring means yieldingly resisting movement of the piston-like element relative to the piston. As shown, the device is inserted in the line 16 to the rear wheel brakes 22 of a vehicle from a master cylinder 20 which supplies the front wheel brakes 26 direct. The housing 10 of the device has a stepped bore containing a stepped differential piston 34 with a passage 52 through it, and which is normally held against the step in the housing bore by a spring 48. An annular piston-like element 70 having a combined seal and valve seat 72 is slidable in the smaller diameter bore portion 28 and is held spaced from the piston 34 by spring washers 78, 80 and an intermediate ring 82. A mass in the form of a ball 58 is contained in a cage 54 slidable in the bore portion 28 and formed with grooves 62 and passages 64, 69 for free movement of fluid past it. The ball is normally maintained against an annular shoulder 59 by a permanent magnet 56, while a light spring 66 maintains the cage in contact with the element 72. When the master cylinder is actuated fluid flows via inlet 12, passage 64, valve seat 72, passage 52 and outlet 14 to the rear wheel brake cylinders until a deceleration of the vehicle is attained sufficient to cause ball 58 to move away from shoulder 59 and close the valve seat 72, whereupon further build up of pressure in the master cylinder causes pressure in the outlet 14 to build up at a progressively lower rate owing to compression of spring washers 78, 80 by movement of element 70, until the ratio of inlet pressure to outlet pressure is such that further increase in inlet pressure moves the differential piston 42, so that the pressure ratio is thereafter determined by the ratio of the areas of piston 42.