| 摘要 |
<p>1,259,190. Hydraulic brake pressure control valves. AISIN SEIKI CO. Ltd. 22 May, 1969 [25 May, 1968], No. 26086/69. Headings F2F and F2V. An hydraulic brake pressure control valve for reducing the pressure applied to the rear wheel cylinders of a vehicle beyond a certain value, has a stepped piston 12 which has two sections 12a, 12b sliding in respective bores 10a, 10b of a cylinder 10 one end of which is closed by a plug 11 in which a valve member 17 is positioned having a spherical valve surface 17a which engages a conical seat 15a, the valve controlling the hydraulic pressure fed from a master cylinder to the rear wheel brake cylinders via conduits 34, 32, port 31, chamber 16, radial grooves 12c formed on piston 12, chamber 22, port 35 and conduit 14. The front wheels are directly connected to the master cylinder via conduit 33. At low pressures hydraulic fluid passes straight to the front and rear wheel cylinders but on reaching a pressure sufficient to overcome the force of a compression spring 21 acting on piston 12, the piston moves to the left as does the valve member 17 under the action of spring 18 until valve surface 17a seats on valve seating 15a effectively sealing the rear wheel cylinders from the master cylinder. The pressure acting on the shoulder of the larger piston section through a by-pass passage 13 and port 30 then moves the piston to the right to open the valve once more whereupon pressure again acts on the front face of the piston 12 and the cycle of operation is rapidly repeated.</p> |
