PNeumatic CNC Coolant Filter
This is a design for a filter that can be used to clean CNC coolants from CNC machines. This device can help increase factory efficiency, save time & effort for the workers.
DATE
May - June 2023
TYPE
Internship
Product Design
Product Design
RoLE
Designer
DELIVERABLEs
3D models of the device
TOOLS
Autodesk Inventor Professional
problem
CNC machines use a special coolant oil to prevent overheating while doing the machining. This liquid usually contains small fragments of metal. After sometime, the liquid need to be filtered in order to keep the machine working.
goal
Design a Filter machine that use diaphragm pumps to help filter the coolant oil automatically, saving time and effort for the factory's worker.
THE Design PROCESS
I. problem examination:
Approaching this project, I started by examining the CNC machines to gather necessary information related to the design. I examine the coolant cycle, how the CNC machine filtered the coolant, and conducting competitive audit on the current solution available on the market.
Coolant cycle
Examining the filter system at the machine
Belt with hole
Coolant carry tiny Fragments back to the tank
Coolant Tank filled with small metal fragments
Larger fragments in the Waste Bin
Each month, the workers have to stop the machine, open up the oil tank, take out and filter the machining oil, clean up the tank, then pour the oil back to the machine. This is a complicated and time-consuming process. It could take a worker a whole day to clean a machine. Putting this in a larger scale, such as in my department where there are hundreds of machines, this leads to a lot of revenue loss for the factory. Manually take the oil out and filter it could also increase the risk of having an environmental emergency case inside the factory and could be harmful for the workers.
Competitve Audit: Delfin Industrial Vacuum
For this particular problem, a potential solution is to create a device that can automate the process, from taking the oil out of the CNC machine, to filter it and pour it back into the tank. A device like this is achievable andmany companies have been creating them for this special task. However, not every one of them can be applied inside SMC factory.
A solution from Delfin
There are many solutions currently on the market, and the most popular one are the machines from the Italian brand Delfin. These solutions usually have the same features, usually contain a pump, a filter to filter out the tiny fragments, and an output hose to put the oil back into the machine.
II. Beginning the Design Process:
Characteristics of CNC Machines
Volume
The largest CNC machine can contain 260L of machining oil inside its tank.
Placement
All of these machines have the recycled oil tank placed on the ground, underneath the main working chamber. The edge of the oil tank is about 30cm tall.
Time
The desired time to clean a machine would be around 10-20 minutes.
Mobility
The device have to be mobile so that it can be deploy easily by workers everywhere inside the factory.
Power Supply
The factory have a couple of pneumatic air outlet attached on the wall, and they have electric outlets attached really high on the ceiling.
Maintenance
Has to be able to replace or attached additional filters, so that it can filter both large particles and tiny particles with just a filter change.
Pump of Choice
This task consists of industry chemicals, large and small solids particles mixed inside the liquid. Hence, the machine need to use a special kind of pump called Diaphragm Pump. The use of normal pump using gears is risky as the solid particles can clogged the pump. Diaphragm Pump use the movement of two diaphragm using air or electricity to pump the liquid.
Diaphragm Pump Working Principle
Diaphragm Pump
Design Ideas
There are two potential ideas for this device, Fish-tank Principle and The External-stored Principle.
Fish-tank Design
The first idea would be creating a device similar to the fish tank filter. This device would not take the oil out of the tank completely, but it will filter the oil portion by portion.
CNC Machine cannot be fully cleaned
Oil is not fully taken out of the CNC machine tank, the workers do not have any way to clean up the oil tank, scrap off the sticky dirt. Some fragments might stay in the oil tank.
Increase price
To fully filter the oil, the pump has to be able to let large particles going through. If the particle is larger than the pump limit, it can create a clogging risk for the pump. To fix this, an Initial Filters could be placed at the input hose to stop the big particles from coming inside the machine.
Faster & UninteRrupted
Faster to deploy & the filtering process is faster, and can be use when the CNC machine is working.
The second idea is a device that could take the oil out completely and filter them externally.
CNC Machine can be fully cleaned
This devsign would leave room for further cleanup of the oil tank, the worker can use brush and tools to scrapes out the sticky dirt.
Bigger in size
This design would be much bigger than the previous idea since it needs a minimum of two internal tanks to store the pre-filtered oil and filtered oil.
Slower & Interrupt the CNC MAchines
Because the coolant is removed from the CNC machine, the machine will have to be stop until the filtering process is cleaned.
External-stored Design
III. The Designs:
Because of the time limit, I decide to choose the fish-tank principle, and create 3D models using Autodesk Inventor Professional. I try to create two different models for this design, one made from shaped aluminum and other easy to find material, the other is the better looking version, yet the manufacturing process would be more complex.
Fish-tank Principle design
This is the design concept for the fish-tank idea. The device consists of one input hose, connect to the top of the device tank.
The tank is seal with a rubber ring, and can be open via a latch. Inside the tank is a bucket with holes. To filter the oil, a filtering cloth can be put inside this tank. The flow rate and the filter size limit can be adjusted by changing the cloth.
The bottom of the tank has a hose to connect it to the input of the Diaphragm Pump. The output socket of the pump is connected to the output hose.
The pump is powered using pneumatic air. The pneumatic air can be put through the FRL module produced by SMC. This module is used to filter, regulate and lubricate the pneumatic air controlling the pump.
However, this design is not completed and need to be tested to receive feedbacks. One problem might be the pump will not generate enough pressure to get the oil coming into the tank, since the tank is placed before the pump. If this issue rises, one viable solution would be installing another Diaphragm Pump before the oil tank.
The tank is seal with a rubber ring, and can be open via a latch. Inside the tank is a bucket with holes. To filter the oil, a filtering cloth can be put inside this tank. The flow rate and the filter size limit can be adjusted by changing the cloth.
The bottom of the tank has a hose to connect it to the input of the Diaphragm Pump. The output socket of the pump is connected to the output hose.
The pump is powered using pneumatic air. The pneumatic air can be put through the FRL module produced by SMC. This module is used to filter, regulate and lubricate the pneumatic air controlling the pump.
However, this design is not completed and need to be tested to receive feedbacks. One problem might be the pump will not generate enough pressure to get the oil coming into the tank, since the tank is placed before the pump. If this issue rises, one viable solution would be installing another Diaphragm Pump before the oil tank.
Takeaways
This project is a valuable experience for me. I gained hands-on experience with designing. I followed each step carefully, from examining the problem, researching current solution on the market, defining requirements, creating 3D models for my idea.
Through this project, I became familiar with the factory's machines, the factory's procedures, and 3D tools like Autodesk Inventor Professional. I also got the chance to apply the knowledge learned in courses like Fluid Mechanics, Dynamics, and Pneumatic to this design project.
Through this project, I became familiar with the factory's machines, the factory's procedures, and 3D tools like Autodesk Inventor Professional. I also got the chance to apply the knowledge learned in courses like Fluid Mechanics, Dynamics, and Pneumatic to this design project.
Key Learnings
Engineering Design Process
Examining the problem, defining the design requirements, creating 3D models.
Autodesk Inventor
Improve proficiency in using Autodesk Inventor to design mechanical models.
Apply Knowledge
Apply knowledge in fluid mechanics, dynamics & pneumatic system in the project.