Warren Nakkela Posted February 2, 2009 Share Posted February 2, 2009 Hydraulic Power Hammers, Has anyone tried to make one. You tell me first and I will say what I have in mind. Probably will anyway. Warren Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 2, 2009 Share Posted February 2, 2009 Oh yeah, here's just one.FLUID-POWER HAMMER So, what are you thinking of? Frosty (who LOVES brainstorming) Quote Link to comment Share on other sites More sharing options...
NeatGuy Posted February 2, 2009 Share Posted February 2, 2009 I read the text of patent at the uspto and I believe that the term fluid is used loosely to describe anything that would flow. In the case of the aforementioned power hammer I would suggest air. brad Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 2, 2009 Author Share Posted February 2, 2009 (edited) This idea has elements of a KA 75 and a Drop hammer, and and could be called a striker rather than a power hammer. A heavy block of iron for an anvil with two upright hammer leads guiding a 300 to 400 pound hammer. A helve is linked to the hammer for lifting the hammer by a hydraulic cylinder. The cylinder is attached to the helve at perhaps a one to eight ratio and the cylinder has a heavy rod to increase the speed on the rod end and hence the downstroke. The valve is operated by a foot controlled rocker to allow a short or long drop, maybe up to, say, 36 inches. Still brainstorming, is it possible to have a more compact speed multiplying linkage instead of a helve. (scissor linkage?) Enough for now. Frosty, it's your turn now. More Thoughts: One could make the hammer cycle automatically by making spring loaded toggles to operate the valves and through adjustable pallets to vary the stroke length. One could make a shifter to go from foot operated to auto. Warren Edited February 2, 2009 by Warren Nakkela More ideas Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 2, 2009 Author Share Posted February 2, 2009 So if one could devise a monkey motion to multiply the speed of the hammer while keeping all the forces balanced and on the center line, then the hammer guides will not be subjected to any bending forces. It also won't take much floor space. Warren Note to Frosty: What do you think? Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted February 2, 2009 Share Posted February 2, 2009 A conventional board-type drop hammer is very close to your description.Forging Check out this link for a picture. Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 2, 2009 Author Share Posted February 2, 2009 Board drops have been around for a long time. My brainstorm tries to shorten the drop by accelerating the hammer velocity and, hence, the cycle time. Any ideas would be a good exercise. Have hope Spring will soon be here. Warren Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted February 2, 2009 Share Posted February 2, 2009 Use coil springs at the top of the stroke - slam it up, slam it down (starting to sound like a mechanical power hammer). Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 3, 2009 Share Posted February 3, 2009 Brad: The Nazel Fluid Power Hammer uses hydraulic fluid in place of air. It is a true hydraulically driven hammer. In truth the only significant differences between the hydraulic and pneumatic drive hammers are the sizes of the ports and the pressure bypass valves. The hydraulic hammer needs larger ports between the drive and tup cylinders as it moves with more resistance than air. The pressure bypass valves are absolutely necessary or the hammer would destroy itself on the first impact. Warren: A couple things: First, are you considering returning and driving the hammer hydraulically? Second, why a helve? To multiply the stroke length with a lever you reduce the power at the hammer by the same ratio. To increase the velocity of the hammer to make up for it requires a MUCH more powerful cylinder. More power means either higher pressure (more dangerous) or larger diameter cylinder which means more fluid. In other words If you use a smaller diameter longer stroke cylinder to drive the hammer you end up with the same end product without adding a layer of complexity, friction and potential failure. I don't know if anyone has tried driving a Kinyon type utility hammer hydraulically but I can tell you for sure you'll need to enlarge the ports 2-3x minimum or it'll be really s-l-o-w. If you're considering building a hammer take a look at Massey's Pneumatic power hammer patented Aug. 1902 #707,246 It's best to print it all out so you can read the description while looking at the drawings. It's written in early 20th c. English legalese. That's England English legalese. Anyway, it has about the simplest control valving I've ever seen on a power hammer, once you realize all the drawings of valves are of the same valves in different positions as described in early 20th. C. English Legalese. A few years ago a fellow had his self contained hammer built but couldn't figure out how to valve it, later patents have valves that require some serious machine shop equipment skills. He tried valving it with simple 1" dia. 1/4 turn ball valves and his hammer ran like a champ. The downside to not having control valves with integral check valves (this is why you really need to go over the patent well enough to know what I'm talking about) the hammer rests on the anvil at idle instead of up. It also won't clamp or do a dead blow. What I does do however is cycle like a big boy. Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Yep, that's the idea, mechanical power hammer. But not quite, Too light for a drop hammer, Too slow for a power hammer. And not for closed die forging. But I betcha it will hit hard and really move iron. Why is Frosty silent? I think I know. His gears are still turning. Can't imagine what that genius will come up with. Hope he's not froze up. Keep up the hope, Spring is coming. Warren Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Ya beat me, Frosty, by two minutes. Thought you were icebound. Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 3, 2009 Share Posted February 3, 2009 Ya beat me, Frosty, by two minutes. Thought you were icebound. And isn't that better than getting beat FOR two minutes? We don't icebind easy, we're equipped to deal. It IS cold enough I don't want to go outside if I don't have to. I had to though, had to drive to Anchorage to see the sawbones, then to do PT, then to pick up some grub for dinner. Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 The reason I thought one need a mechanical speed multiplier was/is that one does not need 6280 pounds to lift a 400 pound hammer. (two inch cylinder 2000 psi.) I feel that one can use part of this force to gain velocity. That is to outrun the gravitational fall of the hammer. I am not sure if that can be done with direct cylinder connection. What is surly needed is a pressure relief valve between the control valve and cylinder to prevent overpressure in the event the valve is closed as the hammer is falling. Also needed are large and short hydraulic line to limit fluid friction loss. Warren Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Frosty, I don't think that I could last for two minutes anymore. Warren Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 3, 2009 Share Posted February 3, 2009 A Nazel 4B (approximately 400lb tup) has peak PEAK shock load pressures in the 15lb. (fifteen) range. Applying 2,000psi in a high impact situation like a power hammer will develop enormous shock loads and blow you to kingdom come in the first few seconds of operation. Besides, adding a hydraulic component to a mechanical device will introduce more entropy than adding a mechanical component to a hydraulic device. You will need to drive the hydraulics mechanically then convert hydraulic motion back to mechanical. The only ONLY reason to do so that makes any sense at all in a forging hammer is to gain control over the forces. If you check out the basics of a pneumatic or Nazel fluid power hammer you'll see the bare bones are as simple and elegant as basic hydraulic brakes. Personally I think the increasing complexity of the valving and hammers themselves were more marketing than need. Who wants to buy something designed 20 years ago when the other guy is offering "cutting edge" technology? Dinner's up, Later. Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Frosty, I think I am lost. First off this is nothing more than an exercise in physics. Unless a block of iron falls from the sky I won't be building one of these anytime soon, still, you never know. I am buying a 75# Bradley so I will be occupied with that. It will take 3 phase but then I will also be able to run my other lathe, this shaper, hydraulic press and ironworker. 2000 psi is common, if not the standard, on farm machinery. Many cylinders have mechanical stops. This causes no problem even when holding the valve open. Tractor valves, however, just kick into center when the pressure spikes. Overpressure protection in necessary for safe and trouble free operation. Warren Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Kingdom Come may not be a bad place. Many people, including myself have gotten a hot oil bath from blown hydraulic lines. This is from equipment operating at pressures of 1500 psi and above. Unlike compressed gasses, liquids under pressure present no explosive hazard if not under accumulator pressure. (closed center systems) Blowing hydraulic lines is not a quick route to Kingdom Come. Warren Quote Link to comment Share on other sites More sharing options...
nonjic Posted February 3, 2009 Share Posted February 3, 2009 Compressed air acts like a spring. Springy is good in a hammer. Oil does not act like a spring. In a press it is being pushed all the time by the pump. Hammer ram velocity is not constant. therefore you cannot push it to get a 'struck' blow, you will only get a fast press. For a hydraulic hammer therefore you need to store some energy somewhere. Back to compressed air! - whack a decent accumulator into the loop and you have your stored energy (think of it like a battery to help with the surges of energy needed!). The hydraulic hammers I have worked with either use a bagged accumulator, or nitrogen over oil. Done right they hit very very hard, and can be beautifully controlable, done wrong, well it can get messy, very quick! Quote Link to comment Share on other sites More sharing options...
NeatGuy Posted February 3, 2009 Share Posted February 3, 2009 Frosty: Beggining at line 50: In the operation of the mechanism, when the downward movement of piston 6 forces air through passage 5 beneath the piston or ram head 18, the air above the ram head escaping through passage 4, the ram 16 rises freely until the stem 11 on the stationary cylinder 9 enters the corrisponding recess 19 in the bottom of the ram. Nazel may have made a hydraulic power hammer, but this patent is for a ram cushioning mechanism in a air hammer. brad Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 3, 2009 Share Posted February 3, 2009 (edited) Warren: Under normal operating conditions what you say is correct. However a hydraulically driven hammer is something entirely different unless specifically designed for forging. Consider the magic of hydraulics is the incompressability of fluids yes? To attain speed you must either have a lot of fluid exchange or a small ram diameter. In either case if the ram is directly connected to the hammer without a substantial bypass pressure spikes when the hammer stops will be big. It's typically a couple x max operating pressure and this is for normally operating rams, say the slide base on the drill. It was common to see the hoses jump and see the psi gage spike to 1,500psi from a working psi of about 750-800 psi. on the rig. If we bottomed out the fast retract you'd see 3,000psi from the same working psi. Now, consider you are transferring a large volume of oil to fill a large cylinder. (small dia, long stroke say) The ram is moving right along, say 30mph with 2,000psi behind it and comes to a screaming halt when it it hits the work on the anvil. You might see pressure spikes in the 20,000psi range and even though what you say about typical hyd leaks and cylinder bursts is true, the consequences of being in the line of fire of this kind of leak or burst is . . .BAD. Give a hospital a call and ask what the procedure is for someone who has had hyd oil injected through their skin. Ask someone who has served on mil aircraft or ships how they go check for a hyd leak. This doesn't take into account pieces of cylinder that may get blown out in a failure. In these types of applications high volume LOW psi is the standard for safety reasons as well as much MUCH lower operating temps. John: A self contained hammer moves the air or hyd fluid with a compressor or master piston on a crank. As the master goes up, the tup goes down. Being as it's driven with a crank the acceleration is described by a sine wave. There is hesitation in a pneumatic hammer as the air compresses and decompresses. Reaction is immediate in the hydraulic version. Pressure spikes must be able to escape over bypass via a very short route to avoid damage and over heating. Brad: Nuts! I should've read the thing. NAZEL built a fluid power hammer by that name that was indeed hydraulic rather than pneumatic. I recall being impressed they had so much confidence in their bypass valves, it scared me just reading the patent. Now I can't find the thing again without reading hundreds of entries. I've seen what happens when a fast moving hyd cylinder with a load behind it comes to a hard stop. Frosty Edited February 3, 2009 by Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 3, 2009 Author Share Posted February 3, 2009 Frosty: This whole exchange is for people like myself to gain knowledge. What I have discovered so far is that the hydraulic components should be enclosed by steel guards in the event of component failure. Not difficult on fixed machinery and powered by five hp or so. Warren Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 3, 2009 Share Posted February 3, 2009 It's brainstorming. Throw out ideas with wild abandon and THEN poke holes in them till maybe a gem filters through. So far there's only been one real idea and someone has to play devil's advocate. A few years ago I spent mucho time surfing the IBM patent server looking for ideas for making a power hammer. I spent I don't know how many hours with graph paper and pencil trying to come up with a control valve for one. Then I ran across the 1902 Massey patent. Actually I'd saved it some time previously but hadn't printed it out so I guess it was then I really LOOKED at. What a revelation. Energy takes the path of least resistance. Whoo! There's a head slapper. All you have to do is give it an easy way out and that's where it'll go! EGADS! I felt like a prize idiot. The flow diagram for one of these is almost unbelievably simple. All I need is a large enough chunk of steel or iron for an anvil and I'll build one of these things. The valving is actually simpler, more robust and far less likely to fail than a Kinyon type utility hammer and it doesn't require a big honkin air compressor either. Anyway. How about making up a couple quick sketches of what you're thinking about and posting them. We may be getting entirely the wrong idea from the text description. Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 4, 2009 Author Share Posted February 4, 2009 I will send this drawing when/if I make my scanner go. Warren Quote Link to comment Share on other sites More sharing options...
Frosty Posted February 4, 2009 Share Posted February 4, 2009 Cool. If that doesn't fly somewhere buried in Window$ is paint or paintbrush or something like that. Before I could afford a decent drawing program I used it to draw machines, tools, etc. Might do the trick. Frosty Quote Link to comment Share on other sites More sharing options...
Warren Nakkela Posted February 4, 2009 Author Share Posted February 4, 2009 While back my computer got sick. Was in the shop. Scanner must have got turned off. Still prints ok. Will see my wizard tomorrow. Will keep the gears turning. Warren Quote Link to comment Share on other sites More sharing options...
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