| 摘要 |
Automatic directional control valves are components for oil hydraulics for the simple control of oscillating or transport double-stroke movements of working cylinders on prime movers. They mainly require only a continuous electrical signal for the time of the controlled oscillating movements or an electrical starting signal for performing a transport double stroke. In accordance with this object, their construction is very complicated or involves high production accuracy, so that there is definitely a market for a simple, inexpensive solution. This problem is solved by the invention by the fact that a differential pressure change, acting on the end faces of a control spool (2), for the automatic control is formed by choke bores (3) which close in a functionally correct manner being connected to the pressure-medium discharge (T) and by choke bores (4) being connected to the pressure-medium feed (P). The said choke bores are continuously connected by the bore (6) and the choke (9) to the end chamber (20) and form a reversing differential pressure as a function of the effective pressure of the pressure medium in the end chamber (15). Choke bores (5) as functionally correct intermittent connection between pressure-medium feed (P) and working connection (B) serve as an aid for the automatic reversals of the control spool (2). An electromagnet (21) with the displaceable stroke-centring device (11, 12, 13, 14) provides for the electrical remote control of desired types of stroke and for the ... Original abstract incomplete. <IMAGE>
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