Issues with pneumatic valves for vacuum

[Rudy Bernard]

Hi all, 

I purchased a dual head with accessories on aliexpress. The head is fine and work great, but I have issues with their valves. They just don't seem to work in vacuum but they are when reverse (compressed air). I use 24V and I have confirmed that there is really 24V on the solenoid. I'm a newbie in pneumatic valve system so I don't want to say that the seller made a mistake (yet). I'm currently in communication with him, but I would like to have some advises from you guys if you have more knowledge than me on pneumatic valves.

Here are the diagram show on the valve (4V110-06). They are all the same.

They provide this schematic which I replicate, but there is no vacuum on the head. If I reverse the air flow, air is coming out from the head so there is no chance that it can grab components. I'm using a small 12V vacuum pump which seem to work just fine.

Any help would be appreciated.

Rudy

[bert shivaan]

If you replicated their drawing you would get a vacuum on the one nozzle, but only if you turn the valves on correctly.

The top left think is a vacuum generator. It turns compressed air into a vacuum. So in that picture, they have compressed air coming into the valve manifold from the right.

When you turn on the left valve, compressed air is applied to the vacuum generator. It will then create a vacuum on the nozzle AS LONG AS the second valve from the left is NOT energized. When you energize it, compressed air will be introduced to the nozzle and compete with the vacuum. The compressed air will win and the part will come off.

No need for your vacuum pump.

Likely the valves will not work in vacuum.

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[bert shivaan]

It may work in vacuum, but then you need to try simply appling the vacuum from your pump to the right side where the compressed air is. Then check for vacuum where the tube comes out the top of the valve.

Disconnect the vacuum generator and the Tee.

[Rudy Bernard]

Hi cncmachineguy,

Thanks for your help! The vacuum generator was label as "Ejector" on the aliexpress page so I tough it was only to eject air or something else. I did notice a vacuum using the compressed air, but it was very weak. My compressed air is done using the output of the vacuum pump since this what I have on hand right now. I suspect this not enough to generate a good vacuum. Will try to find a suitable compressed air pump for this now. Any idea of a model that could work or how many psi is needed?

[Mike Menci]

Hi 

This is Injector system ____ YOU will need to blow in 6-10atm of compressed air - this will produce vacuum on nozzles. https://en.wikipedia.org/wiki/Injector

[Zdenko Stanec]

Hi,

Check my video on how this setup is working 

Link:

https://www.youtube.com/watch?v=nXBxu7lhSCI

Short video description:

There are venturi valves off to the right, the single pressure line comes in the left into a manifold, with all valves closed by default. valve #3 activates suction by blowing into the venturi block, valve #4 activates for a really brief blowoff for that nozzle bypassing the venturi after the manually adjusted valve that limits the pressure.

Br,

Zdenko

[Rudy Bernard]

I saw your video yesterday Zdenko. Seem to be a clean setup, but I wasn't able to confirm the valve model and if you were using compressor or vacuum. Now I know.

Thanks you all, will get my hand on a decent compressor.

[Duncan Ellison]

Rudybe,

I have this exact setup and it works fine, but the 'ejector' or vacuum generator or Venturi (whatever you like to call it) consumes a pretty decent amount of compressed air, your vacuum pump runnin in reverse definately will not generate enough 'puff' to make a vacuum.  

You could completely  dispense with the ejector and simply use your vacuum pump to generate the suck, but failing that, you need to get yourself a small shop compressor.  I recommend the 'oil-less' silent type.  This is the one I'm using https://www.amazon.co.uk/dp/B07TKVSQBR/ref=redir_mobile_desktop?_encoding=UTF8&aaxitk=d480eac8d5ff18a48985d52926f5a199&hsa_cr_id=8140048040102&pd_rd_plhdr=t&pd_rd_r=de4ae5f5-25c7-4ea7-9e03-4effd18fd55e&pd_rd_w=ILvsi&pd_rd_wg=OvWzQ&ref_=sbx_be_s_sparkle_mcd_asin_0_img

[Rudy Bernard]

I made it work with 6 Gallon shop compressor. A bit noisy, but it's in my garage so not too bad. I also add a filter to reduce water as much as possible. Work as expected to pick up parts. Will have to tweak the regulator now to get the best result when real pcb job will be tested. Still few steps of build before fun things begin. Can wait to see it working! Thank you all.