| 摘要 |
<p>1,093,993. Power steering. DANFOSS A.S. July 7, 1966 [July 9, 1966], No. 30587/66. Heading B7H. [Also in Division F2] A valve arrangement for a vehicle steering system, Fig. 1, allows equalization of the pressures across servopiston 2 when the latter experiences impacts from the road wheels. As shown, the piston is supplied from pump 6, control device 7, hydraulic lock 8, Fig. 7, and lines 3, 4. If the piston is moved downwardly by an impact, the increased pressure in line 4 is relieved via line 14, relief valve 15 and drain lines 17, 9, part of the fluid from the relief valve 15 being admitted to the space above the piston via check valve 13 and lines 11, 3. If the piston is forced upwards, the increased pressure in line 3 is relieved via line 11, relief valve 12 and drain lines 17, 9, part of the fluid from relief valve 12 being admitted to the space below the piston via check valve 16 and lines 14, 4. The pairs of valves 12, 13 and 15, 16 are provided with common seat members 27, Fig. 6, each of the latter having an inwardly facing seat for a relief valve ball 43 and an outwardly facing seat for a check valve ball 41. - The seat members have pairs of passages (30, 31) and (32, 33) in orthogonal radial planes, each pair leading from one seat to the opposite end of the members. Plugs 40 retain the seat members in place against shoulders 39 and a common spring 45 loads the relief valve balls. The hydraulic lock valve 8 comprises, Fig. 7, a pair of check valves 53 and a piston 56, the opposite sides of which are connected to the device 7. The valves 8, 12, 13, 15 and 16 are combined in a housing 18 having internal connections indicated in Fig. 1, and ports 19-26 for connection to the other parts of the system. In normal operation, the device 7 supplies one side or the other of piston 2 via chamber 57 or 59 of valve 8, and both valves 53 are open. When the pressure in line 3 or 4 rises as the result of a shock load on piston 2, both valves 53 close to protect device 7 and pump 6 and the pressure is equalized across piston 2 as described above.</p> |
