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| Illustration 1 | g01930413 |
Signal resolver network (A) The valve is shown in the HOLD position. (B) The valve is shown with low pressure. (C) The valve is shown with high pressure. (1) Signal from the pressure duplicating valve (2) Signal (3) (9) Load check valve (4) (10) Pressure compensator valve (5) (11) Spool (6) (12) Feeder passage (7) Pump supply (8) (13) Bridge passage (14) Resolver valve (15) Signal to the pressure duplicating valve (16) Flow to the pump control valve and the signal limiter valve | |
The resolver network consists of a resolver (ball check valve) in each implement control valve. Each resolver compares the pressure signal from the previous control valve and the pressure signal from the current control valve. The resolver ball shifts in order to allow the higher signal to flow to the next resolver.
For example, Illustration 1 shows the resolver network when control valve (C) is activated. Pump oil flow is directed into chamber (7). When control valve (C) is activated, the pump flow is directed into feeder passage (6). The oil in the feeder passage pushes flow compensator valve (4) upward. The pump oil flows through openings in the bottom of the flow compensator valve (4) to bridge passage (8). From bridge passage (8), pump flow is directed around spool (5) to the work port.
When flow compensator valve (4) is pushed up, the oil in bridge passage (8) is also directed through resolver valve (14). The flow of oil is directed to the next resolver valve in the network and to pressure duplicating valve (15). Pressure duplicating valve (15) duplicates the pressure from the resolver network. This pressure is sent to the pump as load signal pressure. The pump then upstrokes in order to increase the output pressure.
If a second control valve (B) is partially opened, the same basic steps happen. The pump flow is directed into feeder passage (12). The oil in the feeder passage pushes flow compensator valve (10) upward. The pump oil flows through openings in the bottom of flow compensator valve (10) to bridge passage (13) in proportion to the movement of the implement control lever for control valve (B). The resolver valve for control valve (B) will not allow oil from bridge passage (13) into the resolver network because of a higher signal pressure from control valve (C). The resolver with the highest work port pressure (C) regulates the flow through all activated control valves.
Pressure compensator valve (10) reduces the amount of pump pressure that is going to control valve (B). Pressure compensator valve (10) uses the signal pressure from duplicating valve (1) in order to limit the pump pressure to control valve (B). The pressure that is allowed in control valve (B) is equal to the pressure that is being requested by control valve (B).