noise at start of opening phase

[mohamed]

could you mind advise me for the following problem i had a 440 ton machine quite new 2017 , during normal operation and at start of unclamping phase,start opening, there is abnormal noise like (TAC) in both situations in dry cycle and with production we check the following
lubricating system
pins of toggle system
try with reducing the clamping force
try with changing the mold

the strange is if i close by clamping and open there is no noise but if i close and wite for 20 sec. then open the big noise appear

[nemanja]

Hi,

Some valves responsible for opening of tool can produce noise like you said. You can tell someone to just open and close tool, or let it run in automatic mode, and try to pinpoint location of noise. Also check tool opening profiles, is speed and pressure of opening tool OK. Sometimes if you have big difference in steps (400 bar to 50 bar or 500 mm/s to 10 mm/s for example) there is "hydraulic jump" that make noise.

BR.

[chrisprocess]

Can't help you much on the maintenance side of the press.

But if your press is hydraulic clamp I'd just say to make sure you have sufficient tonnage and oil flow in your lines for your set speeds..

Example:

15 in/s @ 3 tons - Smooth opening

15 in/s @ 0.25 tons - Not a smooth opening, could result in noises

Just a suggestion! good luck

[SRPlasPros]

could you mind advise me for the following problem i had a 440 ton machine quite new 2017 , during normal operation and at start of unclamping phase,start opening, there is abnormal noise like (TAC) in both situations in dry cycle and with production we check the following
lubricating system
pins of toggle system
try with reducing the clamping force
try with changing the mold

the strange is if i close by clamping and open there is no noise but if i close and wite for 20 sec. then open the big noise appear

Is there a Directional Controlled, lever operated hydraulic valve? I had a problem of the sort on one of the machines I had, it was pretty bad, and we couldnt pin point it. Turns out, it was a limit switch on the operator side door, and our safety valve.

Best Regards!

[bbevc]

Hi! Does that happened now, or is it noise from begining, when machine was new? At hydraulic systems i never know, is it noise, should be noise, or should be silence :) on a couple our machines we have this noise from new. Now they are 10, 12 years old and seems to be fine, this noise cause no problem. When machine need to open, it must reduce clamping force from 4400 kN to 0 in short time. So huge quantity of oil must be removed.it takes a lot of power and that could be loud, just guesing.

[brentb]

Do you have "clamp Decompress" feature on press?
Are you using it?
If not try it!

KOM
brent

[iautry1973]

What type of machines? I know some of the hydraulic Arburgs I used to run made a cracking sound during clamp. Talked to a couple of Arburg techs and they said it was normal. Never caused any issues.