Gantry wash robots vs. articulated wash Robots

The utilisation of robots in the washing machines began for the need to wash different parts in the same machine or the need to high pressure deburr of some areas of the parts .

The german Dürr Ecoclean starts to use the robots in their in-line transfer DGI machines as a complementary high pressure wash of  cylinder blocks or cylinder heads. The parts were transferred in a lift and carry transfer trough the machine an in one station it was the robot with the high pressure jet in the wrist that  works on the part. The robot was located vertical with base at the floor outside the machine with a complete glove on the arm to protect the robot arm inside the machine.

The same philosophy was applied by Stic-Hafroy (now Dürr Ecoclean) ,  ICOM , Valiant , ITF and others. But it happen also the application of deburring small parts like ABS distributors or injectors components where the robot ( or robots) were picking the parts from a pallet and presenting the parts in front of HP jets or lances . In this case the wrist of the robot had grippers for the part and no jets as before.

The”flexibility” of the machine in this case is coming from the possibility to have several wash/deburr programs inside the same machine , but the gripper of the robot need to have at least common points in the component to be washed in order to pick the parts.

Here is appearing the two different concepts on the robotic wash/deburr applications : a robotic wash/deburr operation with a jet moved by the robot against a part transferred by a mechanical system or a robot with a gripper picking the part and moving the part against HP wash/deburr fixed location jets.

In the first case( robot moving the jet) the robot is less exposed to the direct splash of water and there is no mechanical-pneumatic-electric components on the wrist.

 

In the second case (the robot moving the part) the robot wrist is exposed to receive direct high pressure splash , and it has mechanical-pneumatic-electric components on the part gripper risking to be wet .

Some people with experience in robot automation have plunge in the wash/deburr applications with robots gripping the parts without evaluating the additional risk on the wrist. The robot suppliers are working hard to protect the articulated robot but the maximum protection proposed is a IP65 for the arm , with stainless steel covers , and IP68 for the wrist( see my before “post” concerning the IP validity’s). Some of them they are also adding  air over pressure for the wrist. In any case in these applications there is much more risk than in the case of the robot moving the jet.

 In the before post I mentioned the advantages of the Agullo gantry moving the jet at the end of the vertical arm with all the mechanical outside the machine.

 

 

 

The same disposition is adapted by the japanese SUGINO . Sugino is living in the country with more robot suppliers of the world . Why Sugino is not using the articulated robot in their machines? : Because they are more confident with the gantry on the top of the machine than with a robot.

 

 

 

Other manufacturers like the german Arau has presented in the Parts2clean Stuttgart exhibition his robot cell using also a gantry in the roof of the machine. (years before it was using articulated robots inside the machine).Another example is the german Piller that is using the gantry on top of the machine for the HP deburr jet in his cells.

Another advantage of the gantry robot utilisation is that the machine has only one electric control: a CNC known by the users and easy to run. In the case of the articulated robots inside machines , the machine needs a PLC and the robot has his own electronic control( two controls units in one machine).

But the articulated robot has also good points :It can load/unload the part in the machine by himself  when the gantry robot moving the jet , needs of  another transfer device for the parts, it can be produced in advance and customised in the last moment (gripper and programme) ..

So , what a dilemma ¡¡… Yes , and there is another interesting point : the total investment for the machine.

The Robot cells with articulated robots carrying the part are as single  cell an “economic” machine compared with a transfer-robotic  in line machine , or a rotary transfer-robotic machine. But the throughput is not the same.

In a robotic cell loading and unloading the part with the articulated robot you have dead time( load/unload) that penalize the complete cycle of the machine . More big is the part to be washed ( heavier) more time you will spend on the load/unload( lower speed on the movements due to the inertia). The wash time and the blow-off /dry times can not be fully reduced and then there is a need to use several robotic cells according with the requested throughput production .That’s means that you will need two,four.. or five robotic cells versus one equivalent transfer in line or rotary transfer robotic machines.

As a general rule we can say that in the majority of the automotive cylinder blocks and cylinder heads applications the investment is higher with the robotic cells . But is also an strategic choice: you can have one robotic cell as spare , in case of a shutdown in another, or you can increase the production step by step buying the cells in several years … Interesting comparison.

Parts2clean Stuttgart .High Pressure wash/deburr

I remember when AGULLO supplied the first high production (220p/h) washing machine with high pressure water for wash/debur of cylinder heads in the Automotive industry in Europe . It was early in the 1980’s and the High pressure pumps power were for 600Kw. In this time not many companies in the world were able to supply high production machines and the addition of the high pressure was not frequent.

The high pressure installation engineering was a challenge. Not only the high pressure pump supplier didn’t have experience in the 5.500 hour/year continuous running of the pumps but other circumstances were added : working with recirculated water (filtration engineering) , keeping the water at controlled temperature (cooling engineering), keeping the overall noise of the installation (then at 85 dB )(noise insulation engineering), HP safety valves and HP distribution valves reliability , materials used on the HP jets and lances (mechanical engineering) , materials resistance to the HP impact for the fixtures and clamps, vapour exhaust ,vibrations transmission all along the machine,chemical detergents compatibility,flexible hose life…a lot of engineering and innovation.

For many years the AGULLO experience in the high pressure was on the top . Now , 25 years later there is a lot of companies that they say can offer high pressure wash installations.The HP pumps and accessories suppliers have more experience and the technology is better known but , is really so easy , are they selling with knowledgement of high pressure technique’s?… I don’t thing so.

Who are now the companies in the edge?

In the Parts2clean exhibition in Stuttgart I visited SUGINO , as I wrote in my before post who has a lot of experience in Japan on this Installations mainly in low production.

 In Europe we can find one small specialist: Piller in Baden-Wurttenberg(Germany) who has several HP deburr machines types with manual load or robot load ,like the CNC “Vector Jet”cabinets and dominates the deburring range of 400 to 800 bars with water or oil. Their experience comes mainly from the small mechanical components deburr at low production.They had difficulties to supply the complete process of wash,deburr.blow off , dry in one installation but step by step they are finding sollutions to do it using several machines. In Germany is considered as the main experienced supplier. Their clients are mainly germans. As particularity I can highlight that Piller  uses a CNC gantry robot on the roof of the machine moving the HP jet , keeping the part clamped on the table that can have additional CNC axis.

 

 

Another company present in the exhibition is also the german INDA-Markert of the SCHMID group. Indawas an small company with local activity in the high pressure that met Markert with experience in the German automotive market (Mercedes)and transfer washing machines. Both together are now presenting also CNC cabinets for HP operations with HP automatic tool exchange , or rotary transfers, or in line transfers. Out of Germany there are not too active ( out of Hyunday or Kia projects). They were also presenting a robot for deburring gearboxes , with automatic HP tools changer( rotary lances , V-jet , pin point jet..).

 

Of course we can not forget Dürr Ecoclean as global high pressure supplier despite his presence in the Parts2clean exhibition with only one machine for the general market ,the Cmax that I will talk about in a another post. They have the experience and globality that some others don’t have.

Another big specialist that becomes more global is the Canadian Valiant . This company was for years the competitor of AGULLO , and Centry Spray(after Ingersoll) ,and now for Dürr Ecoclean in America.

Valiant is present at the exhibition trough the Austrian TMS company ( body handling) hat now is part of the Valiant group and that will take the responsibility of the Valiant washers/deburr for Europe. The last 5 years of Valiant in USA have been successful , passing for the transfer in line , Ferris wheel supplier to be a complete partnerfor the Automotive industry ,supplying turn key installations with the handling, robot integration,washers(high pressure or robotics),deburr , leak test ,and special assembling machines and AGV transport . Their Aachen Engineering adventure is now forgotten and they seems determined to attack the European market from their new base in Austria. Is the only manufacturer that can compete with Dür Ecoclean as “global” supplier.