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Bosch hydraulic accumulator


ianinsa

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I have a Bosch accumulator and I would guess about 1.5gal. Capacity. I was about to repurpose it into a umo
Burner tank for my foundry but while stripping it I noticed just how well it was made. Said to self 'this looks expensive and too good to junk' and thoughts as to what use I could put it to? Hydraulic hammer? Like a chipper(woodpecker attachment) on TLB?

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Hi Ian,

 

I use one similar to that on one of my Race Cars. I use it to maintain oil pressure in the oil gallery, when under extreme cornering (the oil sloshes away from the oil pick-up and the oil pump cavitates). Sure works well, I've never had an oil starvation problem since.

 

Neil

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i think it's an adjunct to a hydraulic press, but a potentially dangerous one.

I collected a couple of smaller ones to gang up with the right valving.

My hope is to charge them up to full pressure and open the valve to get a full pressure surge

at the moment the dies contact the hot work...without waiting for the pump to build to full pressure.

A major limitation to press forging is the speed that the dies suck th heat out of the work.

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I have a couple of presses some fast some slow one has 3 cylinders 2 vertical and one horizontal. The verticals are 4 & 2" so vast power and speed difference. I've recently found out that one of my mates makes accumulators for use in the deep gold mines. They pump nitrogen into at 110 bar(jiminy crickets). Still thinking about the hydraulic hammer 'woodpecker' idea I just need to figure out the 'how'

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  • 3 months later...

Ian:

Thinking about the hydr presses and the equivalent ambition power hammers..

It seems to me that building for the shock of impact requires considerably more mass and rigidity than a press

where the stresses are simpler and mostly tension oriented.

Wonder if your woodpecker wouldn't be prone to taking itself apart..

I've seen 2, 100 ton forging presses that excellent smiths had made, in use.

It was kinda scary...Those big I beams flexed disconcertingly.

OTOH, Fritz Hagist's late 1800s 100 tonner ( literally hydraulic, pumps water), with it's 4, 4" columns and massive top and bottom cast platens....showed on visible distortion pressing  a 7" ball deep into a hot piece of 1" x 10" X 10" plate.

Had to flip it over and use the press to get it out while still hot.

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Clang,

The 'woodpecker ' attachment in quite common on excavators etc. And they  aren't prone to self destruction. One of the things that I make is impact crushers for the mining industry so I could possibly coble up something relatively strong using 1" plate etc. My interest is not in making a power hammer from it as I already have a 200kg De Moor. I was thinking of something I could use on my mini digger or TLB.

Another member has sent me a PM with info and I'm trying to get my head around it!

As for having a flexing beam, isn't that what they're meant to do? :)  I must admit though I have a really large diameter (380mm) piston in a hydraulic punching press and it's frame doesn't flex, however the thought of one of those steel hydraulic pipes rupturing gives me the willy's.

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Some thoughts on hydraulics, forge presses and accumulators.

Acumulators are very useful in the right application. Using them to damp watter hammer, even piston pump ripple and to provide a short time high flow. An acumulator is nothing more than a way to store a volume of fluid at pressure generated when the demand from the pump is low or zero, for when that flow can be used to suppliment the pump flow. They store energy like a spring, and can release that pressure as suddenly as a spring when released.

 

Having worked in industrial forge shops for about 24 years, I have some strong feelings about hydraulics in forge shops. hydraulics can be very useful and can also kill you quick. Using oil in a hydraulic system ina forge is an invitation to disaster. The "Less flammable" fluids like ethylene glycol are better than oil when a leak occurs, but MUST be maintained at the right dilution to maintain that "less flamable" rating.

If you run the system in a hot shop the water evaporates and if not added back the pure ethylene glycol is FLAMMABLE!

A pinhole leak, under pressure, with the resultant spray crossing a hot forging or forge will make the most awesome flame thrower ever seen.

 

I worked on a lovely B-L-H 4 post forge press for a number of years. 1300 tons. Had 3 each single acting cylinders to press, and a totally manual control system. Having been built in 1913, it ran straight water, which was a good thing as the tallow filled hemp rope packings leaked and sprayed the fluid all over including onto the 10' by 12' press bed. Had a 7 cylinder Worthington pump that also tended to spray a bit. When you wanted to fast approach the work you opened the prefill valve that opened a 12" gate vale to allow water to flood the cylinders and freefall the ram. Once at the work you threw in the pump and the accumulator. What an acumulator! 1000 gallon (approx 4000 liter) and it worked at 1000psi (68 bar). When the pump and acumulator both went into flow that monster really moved and made 1300 tons as it moved!

 

The acumulator had a rupture disc and one day it blew as rupture discs do. The piping for the relief and rupture disc were made wrong, had a sharp 90 degree bend and the thrust blew the pipe off. I was in an office 300' away, with the windows closed as that 1000 gallons of water and air flashed to steam and escaped thru a 2" pipe. Glad I had earplugs as it was deafening. Cleared the boiler shops in seconds. The piping flew about a 100' and knocked a steel frame window out of a structual brick wall!

 

Most modern presses that are very large use a prefil valve and a much more moderate sized acumulator if one is used at all. Pumps are cheaped now and usually now most just have multi-stage pumps.

That press made boiler end caps from heavy plate in WWI, and then made every Victory ship serpentine header made in WWII as well as pressing hemi heads for boiler drums from up to 4" plate that were as big as 12' diameter. When I started in 1981 they were mostly using it to straighten 75' long 24" H-beam. At 250#/foot that was a very heavy beam to move. I was tasked with finding a better way and so I designed up and had fabbed a 1000ton portable straightening press. Portable as long as you have a 20ton or so bridge crane to run it down the lenght of the beam. Sadly that press was scrapped in about 1995.

 

I am fond of 3 nd 4 post presses when I make them. I like to use big all thread and 2H hex nuts. With 3" threaded B-7 rod and the heavy hex nuts one can simply have a think plate burned out to include the post holes and then use a nut on each side on the top and bottom platen. Easy to square as well. I have used this to 50 tons or so.

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