Installing a hydraulic intensifier (amplifier)

[treemuncher]

Does anyone on here have any experience with hydraulic intensifiers?

I have a grapple assembly with a shear arm setup that is only capable of shearing small hardwoods of less than 8" or so as it is currently connected. It should be able to handle 12"-14" diameter stems. My excavator's work circuit is limited to 280 bar or about 4,000 psi but the grapple assembly is designed for 350 bar or about 5,100 psi. Getting another 1,000 psi to the shear should make a world of difference and allow me to cut what I need to take out.

The MiniBooster https://www.minibooster.com/hc4/ and other hydraulic intensifiers like it should be what I need. I'm not sure if I need a separate pressure limiter or if these can be configured to a maximum pressure setting to ensure no damage to the grapple hydraulics.

Any suggestions or experience with these out there on the forum?

 

[Vetech63]

I'm no help. I'm still trying to figure out how it works. Someone explain to me............is this just a secondary relief valve sort of thing? I did notice it had 3/8 inch ports....seems small to me.

 

[skyking1]

I can't think of a way to do this except a pair of cylinders so you'd have to match The strokes and volumes.

 

[excavator]

What brand and model excavator are you working with? Also, which circuit is it running on? 4000 psi seems a bit low for most machines today.

 

[treemuncher]

The machine is a Menzi Muck A91F.

The grapple/shear is a Modularis 12.0 series.

My clamping operation runs off of the proportional foot pedal with a maximum pressure of 280 bar from the machine work circuit. I can not increase the pressure at this valve - already checked.

The cylinders are already in parallel arrangement so that I would only need the amp on the clamping side of the cylinders, not on the release side.

It's a very simple mechanical device that shrinks the effective area to increase the pressure. Some of these work on a rotary principle (from what I understand) while others can be a cylinder that takes pressure from a larger bore then amplifies the pressure via a smaller bore at the other end.

 

[skyking1]

That's what I was talking about, two cylinders or bores to step up the pressure.

 

[mg2361]

I'm still trying to figure out how it works

https://www.fluidpowerworld.com/can-hydraulic-pressure-intensifiers-improve-system-design/

 

[Vetech63]

OK, I see how it is supposed to work. But, wouldnt the 3/8 porting be restrictive on GPM? I would think you can achieve the pressure but you would sacrifice speed to do so.......correct?

 

[treemuncher]

OK, I see how it is supposed to work. But, wouldnt the 3/8 porting be restrictive on GPM? I would think you can achieve the pressure but you would sacrifice speed to do so.......correct?

I'm not set on this particular model or manufacturer. I'm looking for help with sizing and application. I also want something with a built in adjustable HP relief valve and free flow until needed. Something more like this assembly here: https://www.minibooster.com/m-hc-012/

 

[1466IH]

Have never been around anything for equipment like you are looking at but I have been around the ones that take 2500psi and intensify to 10k psi. They are plumbed into a trucks pto circuit to run port-a-power tooling. Have been around both power team and enerpak and both were problematic. Usually just wind up getting out a foot pedal or electric pump anyway.

 

[John C.]

What I see is a short stroke cylinder with a large piston pushing a smaller piston. The higher pressure would only happen after the stroke of the implement cylinder had reached it stop point for the application. Say you grab something and hit system pressure, the cylinder would then move the intensifier piston to increase pressure on the cylinder. The problem I see is that if you are working something that has to move as the pressure is raising, you only have the oil available inside the intensifier for movement. I didn't see anything in the valving that would allow continuous operation above the system set pressure. My thought process is if the intensifier cylinder is 12" long and my implement cylinder is twenty inches long and the project would require 14" of travel on the implement cylinder at the higher pressure, what are you supposed to do next? Release it and let the intensifier cylinder return to start position and try again?

Wouldn't it be better to increase the size of the implement cylinder to get the same force without adding the complication of an extra component?

 

[treemuncher]

Most of these run a micro pump system from the lower pressure:
"When pump pressure is reached on the high-pressure side H, valves KV1, KV2 and DV will close. The end pressure will be achieved by the oscillating pump units OP1 and OP2 by turns. The unit will automatically stall when end pressure on high-pressure side H is reached. If a pressure drop on the high-pressure side exists due to consumption or leakage, the OP1 and OP2 units will automatically operate to maintain the end pressure. It is possible to change the high-pressure connection H to the opposite end of the booster."

I've written to the grapple manufacturer to see what I need to do. I doubt that there is room on their design to put in larger size hydraulic cylinders.