[Emc-users] OT: Mazak turret clamp problem

[Leonardo Marsaglia]

Hello to all.

I have a little problem (I hope it's a little one) with the claping on the
turret of the Mazak QT20.

The clamping works with a hydropneumatic system and by looking at it, it
has some amplificators of force on the back of the charriot.

The problem is, the turret won't unclamp sometimes, and if it does it takes
a little while. Then when it clamps again sometimes I can see it's not a
soft and natural clamping. We checked and replaced the o-rings on the
turrent side, and I checked the electrovalves on the back. The valves
seemed to be a little sticky on the return stroke but I cleaned and
lubricate them and by hand the worked ok. I don't know if that could cause
the erratic problem.

Another thing that happens when the turret doesn't want to unclamp, is that
the air relief on the electrovalve keeps blowing until I turn off the
machine or until I press the clamp button again. (When this happens the
turret doesn't even want to unclamp).

I can't find any docs about the circuit, and I don't have schematics about
the hydropneumatic circuit on the manuals I have. So I came to the only
place I know I will have the best answers :)

Thank as always!

[Sarah Armstrong]

Check also any bearings and thrust bearings for wear, sometimes the turret will not lift parallel, hence they stick

⁣

Sent from BlueMail ​

Post by Leonardo Marsaglia
Hello to all.
I have a little problem (I hope it's a little one) with the claping on the
turret of the Mazak QT20.
The clamping works with a hydropneumatic system and by looking at it, it
has some amplificators of force on the back of the charriot.
The problem is, the turret won't unclamp sometimes, and if it does it takes
a little while. Then when it clamps again sometimes I can see it's not a
soft and natural clamping. We checked and replaced the o-rings on the
turrent side, and I checked the electrovalves on the back. The valves
seemed to be a little sticky on the return stroke but I cleaned and
lubricate them and by hand the worked ok. I don't know if that could cause
the erratic problem.
Another thing that happens when the turret doesn't want to unclamp, is that
the air relief on the electrovalve keeps blowing until I turn off the
machine or until I press the clamp button again. (When this happens the
turret doesn't even want to unclamp).
I can't find any docs about the circuit, and I don't have schematics about
the hydropneumatic circuit on the manuals I have. So I came to the only
place I know I will have the best answers :)
Thank as always!
--
*Leonardo Marsaglia*.
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[TJoseph Powderly]

i dont have an emc solution
i dont have a solution specific to your machine
but we used a system and a plc that may be an idea

(we integrated a load of toolchangers from different companies to
Heidenhain and Fanuc controls)

1st we used a pressure sensor for the entire system,
we didnt attempt tool change if pressure was low
this idea can be used on the line where

"""the electrovalve keeps blowing until I turn off """

valves can be used to isolate the line in question and test for backpressure

and for the good/bad clamp issue
we had a solenoid with a line and another pressure sensor
it fed a tiny hole on the clamping surface
IF the tool seated well, it would stop air flow after a short ( 100mS )
time , pressure would rise
IF the tool was NOTSEATED the code could try again a few times before
aborting and signalling, pressure would NOT rise
IF the tool was NOT UNCLAMPED we could also try to re-release in the PLC

by using 'backpressure' we could evaluate the seating/releasing of the tool

HTH
tom tjtr33

Post by Leonardo Marsaglia
Hello to all.
I have a little problem (I hope it's a little one) with the claping on the
turret of the Mazak QT20.
The clamping works with a hydropneumatic system and by looking at it, it
has some amplificators of force on the back of the charriot.
The problem is, the turret won't unclamp sometimes, and if it does it takes
a little while. Then when it clamps again sometimes I can see it's not a
soft and natural clamping. We checked and replaced the o-rings on the
turrent side, and I checked the electrovalves on the back. The valves
seemed to be a little sticky on the return stroke but I cleaned and
lubricate them and by hand the worked ok. I don't know if that could cause
the erratic problem.
Another thing that happens when the turret doesn't want to unclamp, is that
the air relief on the electrovalve keeps blowing until I turn off the
machine or until I press the clamp button again. (When this happens the
turret doesn't even want to unclamp).
I can't find any docs about the circuit, and I don't have schematics about
the hydropneumatic circuit on the manuals I have. So I came to the only
place I know I will have the best answers :)
Thank as always!

------------------------------------------------------------------------------

[Leonardo Marsaglia]

Hello Sarah and Tom.

Thanks for your quick reply. I have checked the valves and solenoids again
and they are alright. Bearings were ok when I disassembled the whole turret
to change the o-rings on the main piston.

I finally solved the problem, by reducing the amount of oil on the hydro
booster's oil tank. Apparently there was too much oil in there. Now it's
working and it's also clamping and unclamping a quicker. I also cleaned the
tank to ensure there were no particles or debrys.

It's been working for several hours now without any symptom so I hope it to
stay like that.

Post by TJoseph Powderly
i dont have an emc solution
i dont have a solution specific to your machine
but we used a system and a plc that may be an idea
(we integrated a load of toolchangers from different companies to
Heidenhain and Fanuc controls)
1st we used a pressure sensor for the entire system,
we didnt attempt tool change if pressure was low
this idea can be used on the line where
"""the electrovalve keeps blowing until I turn off """
valves can be used to isolate the line in question and test for backpressure
and for the good/bad clamp issue
we had a solenoid with a line and another pressure sensor
it fed a tiny hole on the clamping surface
IF the tool seated well, it would stop air flow after a short ( 100mS )
time , pressure would rise
IF the tool was NOTSEATED the code could try again a few times before
aborting and signalling, pressure would NOT rise
IF the tool was NOT UNCLAMPED we could also try to re-release in the PLC
by using 'backpressure' we could evaluate the seating/releasing of the tool
HTH
tom tjtr33

Post by Leonardo Marsaglia
Hello to all.
I have a little problem (I hope it's a little one) with the claping on

the

Post by Leonardo Marsaglia
turret of the Mazak QT20.
The clamping works with a hydropneumatic system and by looking at it, it
has some amplificators of force on the back of the charriot.
The problem is, the turret won't unclamp sometimes, and if it does it

takes

Post by Leonardo Marsaglia
a little while. Then when it clamps again sometimes I can see it's not a
soft and natural clamping. We checked and replaced the o-rings on the
turrent side, and I checked the electrovalves on the back. The valves
seemed to be a little sticky on the return stroke but I cleaned and
lubricate them and by hand the worked ok. I don't know if that could

cause

Post by Leonardo Marsaglia
the erratic problem.
Another thing that happens when the turret doesn't want to unclamp, is

that

Post by Leonardo Marsaglia
the air relief on the electrovalve keeps blowing until I turn off the
machine or until I press the clamp button again. (When this happens the
turret doesn't even want to unclamp).
I can't find any docs about the circuit, and I don't have schematics

about

Post by Leonardo Marsaglia
the hydropneumatic circuit on the manuals I have. So I came to the only
place I know I will have the best answers :)
Thank as always!

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