Komatsu PC 180-LC3 Extra Hydraulic

[Antti]

Hello,

Does anyone have a solution how to get out both pump flow to external hydraulic from PC180-LC3 excavator?
I am planning to add equipment what needs both pump flow but nowadays there is only external hydraulic for bucket tilt (one pump)

I might need to add some extra valve where to get flow out, but big question is how to controll the pumps?

Does anyone know how this "hammer" hydraulic is done in PC210-LC3?
What i have seen there is no option to have this similar valve to PC180-LC3 machine, do you know why?


Thanks in advance,
Antti

 

[John C.]

You have one auxiliary valve on the Dash 3 machines. It was only single pump flow. We generally would run that circuit for a thumb. You could also run a breaker or compactor with it but you had to route the return oil directly to the return circuit and not go back through the valve. That limited the size and flow of the attachment.

There are two separate valve banks on the Dash 3 machines. One pump feeds one side and the other side is fed by the other pump. There are two spools feeding the boom and stick circuits, one spool in each valve. When you raise the boom both spools would open and each pump would feed into the boom circuit. When you extended the stick both pumps would feed that circuit but when you pulled the stick back in only one spool would open which would keep gravity from putting a negative pressure on the stick cylinder. The is a straight travel spool in one valve block so that when you were traveling and operated another function that valve would open and join both valve banks together.

The only way we were able to get two pump flow for an attachment was to put diverter valves between the pumps and control valves. This was in the early days of tree processors and mulchers. The initial thought was that enough flow would drop from the jet sensors when the diverters sent oil out that the differential pressure would stroke and destroke the pumps. The first problem was calibrating the diverters for the required flow and then hoping the differential pressures would be close enough to keep from overheating the fluid and engine and maintaining the proper flow for the attachment. The diverters at that time had drilled orifices so it was a guessing game to get each side with equal amounts of oil. When that didn't work right we put pilot controlled valves on the jet sensor lines to drain off some pressure to control the pumps when the attachment was running. All this was real complicated and never really worked at an optimum level. The Dash 6 line solved all that by having the stack valve that could be either single or dual pump flow and still keep the load sensing functions.

Good Luck with your project.