Previous in Forum: Vortex Breaker for LPG SPherical Tank   Next in Forum: Mechanical Pumps and Pressure Boost
Close
Close
Close
6 comments
Anonymous Poster

Robotic Pick and Place Machine - Malfunctioning Air Cyclinders

05/10/2009 9:43 PM

Hi,

I am using a Robotic Pick and Place machine.In my machine we are using Air Cylinders to clamp and unclamp the Boards in the conveyor for placement purpose.

Hence we are facing clamping issues in some of the machines very freqently,last week also we replaced one air cylider in one of the machine and after it was working fine.And two days before also we faced this same issue in some other macines and for this also we replaced a new air cylinder in this macine and after it was working fine.

And in both the problematic Air cylinders i found a crack on the outside surface.So my question is, it is possible of getting a crack on the surface of the cylinder.Hence it is not rubbing anyware.Pls explain me.

Thanks

Reply
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
3
Power-User

Join Date: Aug 2007
Location: N.E. Alberta 55.6329 N Lat. 111.0729 W Long. Canada
Posts: 216
Good Answers: 7
#1

Re: Air Cylinders are not working properly

05/11/2009 4:27 AM

Over pressure, shock load, under rated cylinder, poor manufacturing, bad air (moisture), faulty regulator, no regulator, leaking internal seal, boards slamming into rod end.

You might have to sit and watch the thing for many cycles to see what's causing you grief. The whole thing might be moving too fast for the eye to pick up, so a strobe light or high speed camera could help.

__________________
Could be worse, it could be me. :)
Reply Good Answer (Score 3)
2
Guru
Philippines - Member - New Member Engineering Fields - Instrumentation Engineering - New Member Engineering Fields - Control Engineering - Who am I?

Join Date: Oct 2006
Location: Philippines
Posts: 2075
Good Answers: 51
#2
In reply to #1

Re: Air Cylinders are not working properly

05/11/2009 9:18 AM

From my experience, a cracked pneumatic cylinder is caused by the lack of speed control on the piston's movement. The piston moves very fast and slams against the end stops. When you add the mass that the cylinder is moving, the shock can get very strong.

One solution is to install flow or speed regulators to slow the movement down.

Another is to replace your existing cylinders with the ones that have built-in soft-stop. As the piston nears the end, it covers the main exit port and a smaller port comes into play. This slows down the piston and allows it to contact the end stop with less force.

regards,

Vulcan

__________________
Miscommunication: when what people heard you say differs from what you said. Make yourself understood.
Reply Good Answer (Score 2)
Guru
Hobbies - CNC - New Member Hobbies - DIY Welding - New Member Engineering Fields - Electromechanical Engineering - New Member

Join Date: Aug 2007
Posts: 22637
Good Answers: 409
#6
In reply to #2

Re: Air Cylinders are not working properly

05/12/2009 9:30 AM

As you stated later in your post.

Another solution is to have Bumpers on the Extend and Retract end. Both are options.

Contact your supplier or Cylinder Rep. and explain to him your issues.

Identify your problem than address it accordingly.

phoenix911

__________________
“ When people get what they want, they are often surprised when they get what they deserve " - James Wood
Reply
Power-User

Join Date: Mar 2007
Location: Newburgh, IN
Posts: 285
Good Answers: 10
#3

Re: Robotic Pick and Place Machine - Malfunctioning Air Cyclinders

05/11/2009 9:38 AM

Sounds like lack of Lubrication to me.

The next time a cylinder stops working as designed, insert some low viscosity lubricating oil directly into it by removing the flow lines at the cylinder and placing a small amount of oil into it.

__________________
Bud Trinkel
Reply
Anonymous Poster
#4

Re: Robotic Pick and Place Machine - Malfunctioning Air Cyclinders

05/12/2009 12:22 AM

Hi,

Because of poor maintenance,uncontrolled air flow,local air cylinder,

need to check the input air,is it moisture coming through air,it will damaged cylinder,because insufficent air,cylinder try to operate in nortmal condition.

put air flow controller to cylinder.

you can check all air cylinders in weekly PM once or Monthly PM.

you can control over all these typr of problems.

vinayaka m.m.

Reply
Associate

Join Date: Jan 2008
Posts: 32
Good Answers: 1
#5

Re: Robotic Pick and Place Machine - Malfunctioning Air Cyclinders

05/12/2009 4:17 AM

I would suspect that you have too much demand on the circuit; on more than one occasion, I have seen the demand output increased to the point that flow is hindered. I would guess from your posting, that this is a new occurrence reflecting from recent changes in your process. Assuming that you have quality pneumatics components, and that your air quality is also good....my next train of thought, is do you have an accumulator installed in the system? Too many times, people think the more is better rule will always apply; but this is quite the contrary.

Pneumatics systems operate off of volume of air instead of PSI of air. In efforts to increase speed for production, many times operators will increase air pressures to the desired part of the system, and although they do increase volume somewhat, they also increase the operating PSI to maximum and sometimes beyond. Usually, this is done because the operation (process) is running so fast that the air system cannot keep up with the dynamics of the operation. In other word's, if the clamping cylinder needs X amount of air to clamp, then it also needs X amount to "unclamp" given the same rate is desired. Let's say that your system is capable through practical design and installation of efficiently running 10X, but in your process to increase production, you want to add some work stations, you add 6X; Even though your PSI source may be rated to handle the demand, can your installed system handle the flow demand and not drop any efficiency? In overhead "power and free" conveyor systems, you will find accumulators installed at various points (usually @junctions for track path changes) simply because the system (air) cannot keep up it's volume versus demand work load. An example would be say a track intersection that is located 600' from the air source, that needs to cycle every 30 to 45 seconds. Let's also assume that it has a large demand request (volume requirement) for stroking and destroking; then you need to have an accumulator installed very near that junction to insure that you always have adequate "volume" to allow proper function. An accumulator will allow you to keep that volume on hand, while the air system gradually replenishes it.

A simple test for this operation (for your maintenance people) is to install a flow meter in the system and monitor the decrease in efficiency as you increase demand; you will find that the "inefficiency" increases dramatically, the further you get away from system flow output, or rating capacity. Yes, you can increase by adding more air pressure, but, you will always decrease your reliability and consistency. How is it efficient to increase productivity by 10%, and then lose it to a maintenance issue that is oft times more than the 10% gained.

old golfer

Reply Score 1 for Good Answer
Reply to Forum Thread 6 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Comments rated to be Good Answers:

These comments received enough positive ratings to make them "good answers".

Comments rated to be "almost" Good Answers:

Check out these comments that don't yet have enough votes to be "official" good answers and, if you agree with them, rate them!
Copy to Clipboard

Users who posted comments:

Anonymous Poster (1); BudT (1); mayt2u (1); oldgolfer (1); phoenix911 (1); Vulcan (1)

Previous in Forum: Vortex Breaker for LPG SPherical Tank   Next in Forum: Mechanical Pumps and Pressure Boost
You might be interested in: Air Cylinders, Hydraulic Cylinders, Rodless Cylinders

Advertisement