WEGEVENTIL

摘要

1387950 Valves ROBERT BOSCH GmbH 18 Oct 1973 [20 Oct 1972] 48698/73 Heading F2V A multiway valve having a slide 23 axially movable within housing 21 to control working fluid flow selectively from an inlet chamber 24 to one or other load connection 27, 28 and from the latter to drain chamber 26 includes ducts 33, 35 in housing 21 forming part of a control line 18 influencing a changeover valve (17, Fig. 1, not shown) for the direct return from source to drain of working fluid, and control grooves 48, 52 in slide 23 co-operating with ducts 33, 35 in respective angular positions of the slide to render the valve suitable for use with double or single acting loads. As shown slide 23 is in its neutral position and angularly disposed for double acting control, indicated by notches 57 on its upper surface, groove 48 in slide 23 permitting flow of control line fluid from duct 33 to duct 35 to thus maintain the change-over valve (17) open so that the working fluid flows directly from source to drain. The width of groove 48 is such that should slide 23 be moved leftwards or rightwards from neutral to direct working fluid from chamber 24 to load connections 27 or 28 respectively then control line flow between ducts 33, 35 is interrupted causing changeover valve (17) to close and prevent direct flow from source to drain. For single acting control, slide 23 is rotated through 180 degrees so that notch 58 is uppermost and control groove 52 cooperates with ducts 33, 35. Load connection 28 is blanked-off by a plug (59, Fig. 5, not shown). Groove 52 is of greater width than groove 48 such that control line flow between ducts 33, 35 is only interrupted when slide 23 is moved leftwards from neutral to direct working fluid to load connection 27. Slide 23 is provided with a pressure compensating groove 49 communicating via an axial groove 51 with control groove 48, the latter connecting via radial bore 53 with control groove 52. These grooves &c. in conjunction with bores 37 in housing 21 ensure that slide 23 is pressure balanced in all positions. Exhaust of fluid from load connection 28, during double acting operation, is via a branched chamber (29, Fig. 4, not shown) in housing 21, through diametrically opposite ports 47 in slide 23 to an axial bore 46, and thence through ports 54 into chamber 26. Accidental rotation of slide 23 between its single and double acting positions is prevented by the slide actuator. Two multiway valves may be combined in parallel to form a block (10, Fig. 1, not shown), one valve (13) being set for double acting control and the other (12) for single acting.