hydraulic motor for screwing mold

[tecnico_plast]

Good morning to all,
I need an opinion on choosing the most appropriate hydraulic engine for an injection mold for threaded parts.
Does the engine serve to unscrew the males from the fingerprints, generally how do you choose the most suitable engine?

 

[Er Presidente]

Good morning to all,
I need an opinion on choosing the most appropriate hydraulic engine for an injection mold for threaded parts.
Does the engine serve to unscrew the males from the fingerprints, generally how do you choose the most suitable engine?

pneumatic no?

 

[PierArg]

I thought they were tires.

 

[tecnico_plast]

Until now we have used hydraulic actuators sauer-danfoss, of pneumatic engines no experience, but I do not exclude that we could use them if there are advantages.
more than anything else I was wondering what criteria were adopted to dimensional the engine?

 

[MBT]

Until now we have used hydraulic actuators sauer-danfoss, of pneumatic engines no experience, but I do not exclude that we could use them if there are advantages.
more than anything else I was wondering what criteria were adopted to dimensional the engine?

I have no experience of molds and similar
However, knowing the hydraulic motors and tyres, in order to choose them I must have some starting data
torque that the engine must provide
number of turns
cycles of operation
boundary conditions

 

[PierArg]

as mbt said, the first thing is to define the couple that must deliver the engine and the number of turns.
already these two data are good starting points.

 

[Enigma]

quoto mbt, the first thing is the project data and then you see the type of engine (if omm, omt, oms, omv, ......)

enigma

 

[tecnico_plast]

In fact, that is the problem:
Let's pretend that I have to unscrew (inside the mold, before the extraction) 4 1" threaded caps, something very similar to the 10 litre plastic caps, to understand.
Once injected, plastic exerts pressure on the fingerprints, and the threaded male must be unscrewed, winning this pressure. This is exactly the point, somehow calculating the couple needed to unscrew x males.
empirically, you can rely on engines mounted on similar molds, which do their job well, but are we sure that they are not oversized?
Moreover, we must also take into account the laps, if the engine is too slow and increases the time-cycle, we risk going out of the market.

 

[MBT]

In fact, that is the problem:
Let's pretend that I have to unscrew (inside the mold, before the extraction) 4 1" threaded caps, something very similar to the 10 litre plastic caps, to understand.
Once injected, plastic exerts pressure on the fingerprints, and the threaded male must be unscrewed, winning this pressure. This is exactly the point, somehow calculating the couple needed to unscrew x males.
empirically, you can rely on engines mounted on similar molds, which do their job well, but are we sure that they are not oversized?
Moreover, we must also take into account the laps, if the engine is too slow and increases the time-cycle, we risk going out of the market.

Well, if it's oversized you can know. . .
If it's a hydraulic engine, you definitely have a control unit. if you have a control unit, you have a connected or connectable pressure gauge (on the minimumss) to the drive line. see what pressure it works and you will know how much torque (about) you need to do the action.
not only, knowing the type of valve that controls the engine, and given the deltap of the plant, you can know indicative of the flow of oil.
therefore, given the characteristic curve of the motor, know how many turns wheel etc etc etc. etc.
from there, thanking xl and with various measurements, you can try a calculation model to know where to go to parare in the next case

 

[PierArg]

Well, if it's oversized you can know. . .
If it's a hydraulic engine, you definitely have a control unit. if you have a control unit, you have a connected or connectable pressure gauge (on the minimumss) to the drive line. see what pressure it works and you will know how much torque (about) you need to do the action.
not only, knowing the type of valve that controls the engine, and given the deltap of the plant, you can know indicative of the flow of oil.
therefore, given the characteristic curve of the motor, know how many turns wheel etc etc etc. etc.
from there, thanking xl and with various measurements, you can try a calculation model to know where to go to parare in the next case

grande mbt!:4425:

 

[Dade73]

technical_plast hello.
In my opinion, the couple you will have to win, imagined beyond all that the caps will be made are a polyolefin material (pp,pehd), is really low. in the last moulds I have made I have always fitted three-phase electric motors (0.8kw) with reducer.
disadvantages: clutter and very slight penalty in the stamping cycle.
advantages: you can achieve the overlay cycle with the opening of the press (using also the external profile of the figure as "antirotation"; avoid that "easy" operators increase the speed and pressure of the hydraulic circuit that feeds the hydraulic motor, the thing can bring back damage to the whole system of gears.
I hope I've been clear
hello and good day
davide

 

[tecnico_plast]

Well, if it's oversized you can know. . .
If it's a hydraulic engine, you definitely have a control unit. if you have a control unit, you have a connected or connectable pressure gauge (on the minimumss) to the drive line. see what pressure it works and you will know how much torque (about) you need to do the action.
not only, knowing the type of valve that controls the engine, and given the deltap of the plant, you can know indicative of the flow of oil.
therefore, given the characteristic curve of the motor, know how many turns wheel etc etc etc. etc.
from there, thanking xl and with various measurements, you can try a calculation model to know where to go to parare in the next case

I know the data because the molding press allows me to manage flow rate and speed.
do these empirical tests however on a mold in operation is not safe, you risk doing damage.

 

[tecnico_plast]

in the last moulds I have made I have always fitted three-phase electric motors (0.8kw) with reducer.
disadvantages: clutter and very slight penalty in the stamping cycle.
advantages: you can achieve the overlay cycle with the opening of the press (using also the external profile of the figure as "antirotation"; avoid that "easy" operators increase the speed and pressure of the hydraulic circuit that feeds the hydraulic motor, the thing can bring back damage to the whole system of gears.

hi davide, we also avoid overlapping the opening of the press, speed and pressure of the circuit are established and set, if someone changes the parameters and harms...if it assumes

at this point would be to compare the advantages/disadvantages between hydraulic, pneumatic and electric motors.

 

[MBT]

I know the data because the molding press allows me to manage flow rate and speed.
do these empirical tests however on a mold in operation is not safe, you risk doing damage.

I don't think you need proof.
if you already have pressure and flow data, you know accordingly torque and rotation speed
analyze this data for various applications, with different size of the lids, and you will get an idea of the torque according to the size. for interpolation or extrapolation you should also understand what you need for a "never used" lid and therefore what kind of features must have the engine

 

[tecnico_plast]

I don't think you need proof.
if you already have pressure and flow data, you know accordingly torque and rotation speed
analyze this data for various applications, with different size of the lids, and you will get an idea of the torque according to the size. for interpolation or extrapolation you should also understand what you need for a "never used" lid and therefore what kind of features must have the engine

In fact, that's what we've done right now.
I thought there was a more accurate study, or a method of calculation. . .

 

[MBT]

Probably.
I don't know how to answer you, never having worked in molding

 

[Jari]

I am against pneumatic engines for this kind of applications.
because if you work with a hydraulic control unit you can work at 80 - 100 bar.
You can't do that with the plant air.

I prefer to use a double reduction, and a small and fast engine.

the rotating shaft that moves according to the thread step, will have to operate a microsw not to arrive
with 80 bar at the mechanical arrest.