Easy accessibility for maintenance

The washing machines for complex mechanical parts like the automobile cylinder block or cylinder heads are like machine tools with a lot of mechanics , hydraulics , pneumatics and electric components.

The reliability of the machine is directly linked with the good working of these components . These components are submitted to very bad conditions compared with a machine tool.Inside a washing machine there is a lot of bad conditions : dust air, humidity , temperature , vibrations, water spraying , chemicals( detergents) , coolants (coming with the parts to be washed) ,chips ,burrs ,.. The conditions are much worst than in a machine tool.

These conditions are very hard for the machine components and the engineering of a good washing machine has to consider as a first task to limit the components inside the washing machine.

This task is not always 100% possible and inside the machine there are also  mechanic components that have to be easy to maintain and repair. For this reason the second task of a good washing machine engineering is to take care of the accessibility to all the components around the machine.

Easy accessibility of the maintenance operator to all the components located outside the machine ( cylinders , mechanics, switches,valves, check valves , distributors…) and also to the inside the machine.

Depending of the machine size and the components inside the machine the accessibility can be made with large doors in order that the operator can access to the component keeping his foots outside the machine.

But in high production machines ,or big machines the operator has sometime to go inside the machine for the maintenance . For that, late 70’s the company Agullo launch a big innovation . A complete wall of the machine , all along the machine was a door with a vertical opening( big size guillotine door). The door received different names trough the times , vertical door , vertical guillotine door , full access side door, full size door … and was rapidly adapted by others manufacturers .

The first installations with these full size guillotine doors we supplied by Agullo to Peugeot and Renault in France . They were driven by a motoreducer and two chains on the top. The door opening was from the roof till the transfer .

The french competitor Stic Hafroy seen the machines in Peugeot and Renault quickly “adopted” this type of door in their machines.

The dimensions for the doors were growing in length (machines with 12mts doors length) and in heigth allowing to the operator to go and walk  inside the machine . Normally the machines were equipped with only one door in one side of the machine , but Agullo supplied also machines with two doors one in each side of the machine.

 

 

 

 

 

As one of the main customers was Ford Motor co. in UK and Germany the competitors in these countries also adopted the full size access door ( Harry Major  , Beys…).

 

 

 

Harry Major

 

In Italy for Fiat the machines had one full size guillotine door in one side of the machine and one corridor all along the machine in the other side allowing the operators to walk all along the machine both sides of the transfer.Seen the machines supplied to FIAT the local competitors Tecnofirma , and ICOM incorporated the door to their machines.

Agullo

 

 

 

 

 

Icom

 

Tecnofirma

 

 

The driving of these doors was progressing from the double chain and one reductor , to the rack and pinion , or gear and pinion and from the top driving to the floor driving , always by cost reduction reasons because the safety was never a concern .

In the 90’s  and 2000’s a lot of machines were supplied to Ford , Chrysler and GM  USA with these doors been accepted on all the customers safety standards.

 

Agullo-Dürr Ecoclean

 

 

                         Agullo/Dürr Ecoclean

 

 

 

In USA the full size guillotine door was also adapted by competitors like Valiant

 

Valiant

 

 

The challenge of these doors is not only the mechanics for the vertical movement for open/close the door but the water leaks and the noise contention. Any small gap on the adjustment to the machine wall could allow the water leaks outside the machine or to rise the machine noise level. The door construction, the materials used, and the design allows to avoid all those problems.

The high production machining lines in the automotive industry needs high efficiency and reduced cost. Few operators are operating the machining lines , and the first maintenance task are made by themselves . The machine needs to be easily controlled , and maintained . The design of the machine has to take in consideration the easy access to all the machine components , the easy and quick dis-assembly and repair . Full access , illumination , clean air, clean access .

Don’t forget : The washing machine needs maintenance because they work on worst conditions than the machine tools. It is a supplier task to reduce the maintenance time needed and also to allow the easy maintenance.

The USA mistake

 

Today I would want to remember the big mistake of some European and Japanese washers manufacturers in the Automotive American industry  middle 1990’s .

Sometime the successful manufacturers of one continent try to introduce their products in other continent without considering the difficulties due to the philosophy of the washer concept in each continent.

Sometime the customers of one continent wants to punish or improve their present manufacturer suppliers buying machines to a supplier from another continent without considering the difficulties due to the philosophy of the washer concept in each continent.

This happened in the 1990’s with the Japanese SUGINO . Ford Motor co placed orders for gear boxes high pressure washers to them(I hope it was in Livonia factory). The machines were of Japanese concept , giving good cleanliness quality but not appropriated to the maintenance requests from the American users ( accessibility , inside room, safety devices, documentation..). In conseque the application was a fracas and SUGINO didn’t had continuity in Ford.

In another case Ford Motor ordered a high pressure transfer wash/deburr for aluminium cylinder heads with also brush deburring.The supplier was the German company Beyss. The machine had a very complete process with brush deburring, cavitation wash, high pressure wash , ferris wheel.

When the machine starts to work in the factory( Romeo?) all the American normal washers suppliers were invited to see and appreciate the top of the technology in washing machines.  Not more than two years later the machine was a nightmare for the client due to his high complexity and the quantity of chips remaining inside the machine .The maintenance was difficult for the customers people,they were not trained for the job( complexity,controls, safety standards..).In consequence the application was a fracas and Beyss didn’t had continuity in Ford. Beyss lost a lot of money .

The American Automobile market had some particularities not present in Japan or in Europe:

 1) The car engines were much bigger . V engines of 3 to 6 litters volume. These sizes in Europe would be considered truck engines , not car engines.

2) The throughput in America was 200 to 300 parts /hour . In Japan or Europe the throughput was between 100 and 125 p/h

3) The tendency in Europe was to install sophisticate automatic filters for the wash liquid filtration with small tanks to have a minimal quantity of  liquid  in  the machine, when in America the tendency was opposite : big tanks simple filters and safety manual bags filters.

4) The amount of chips arriving to the machine with the parts was much bigger ( three to four times) than in Europe.

5) The detergents used in America were restricted to the environmental request of the State and in was not easy to use new ones used in Europe.In America the customers were working at ambient temperature ( witout machine heating)

6) The maintenance request in America were different. The “sizes” of an American foreman were much bigger than the Japanese foreman or European foreman. The machine access had to be bigger and easier in America .

7) The preventive maintenance philosophy in America was different: better to change a mechanical part after a certain number of working hours , than to check frequently how is it ,and evaluate if it has to be changed. It was more a “big maintenance” when needed than an small “periodic maintenance” to prevent a “big maintenance”.

8)The mechanical robustness of the machines in America was bigger than in Europe or Japan ans less sophisticate . For this reason the high production machines were hydraulic driven instead of electromechanical. The American hydraulics  standards were very constrained for the Europeans or Japanese  with inexperience and a high cost for them.

Al theses particularities were not well evaluated by Sugino, Beys… and caused their failure but it was also the pressure of the customers that forced them to deliver without enough analyses of the Market needs.

This was the situation when the company AGULLO arrives to the American market. People in Ford USA saw the Agullo Ferris wheel washing transfer machines in Ford Europe and wants to try it in America.

Then the american premium washer suppliers were Ingersoll (Centri-Spray), and Valiant on the Ferris wheel machines and Rocktool,and Liquiburr( in bankrupt) on high pressure.

Knowing the American particularities , AGULLO arrived to this market with the Ferris wheel machines( in line transfer with two vertical rotary tables across) for the cylinder blocks and cylinder heads.

The machines were in stainless steel body, with big tanks , robust mechanics, total accessibility (full side wall as motorized vertical guillotine door) for the maintenance, high pressure wash, and machine tool mechanics quality. In Chrysler with individual automatic filters , in Ford with Central filtration systems.

These machines astonish the customers and competitors. Some American suppliers commented the machines to be like the  ”Cadillac “of the Washers.

 

 

The majority of the machines are still working and have been retooled for new engines. This is an example to show that the washing machines are specific machines linked to a market and demands of a market and that before to go to other markets ,other customers, other requests,other mentalities, all the details have to be analysed in dip  .

The training of the customer is also important because if the machines are of a new technology for him , the operation and the maintenance is new and without a hard support from the supplier it could defeat.

Years later another example of that happen when one Automotive customer wants to buy exactly the same machines that he saw in Germany working in cylinder heads and cylinder blocks featuring new technologies for the Americans : hot cavitation wash, oil evaporators and vacuum dry. The machines were running successfully in Europe but not in America. Two years after the installation , the customer was enable to run the machines . ( tanks too small , foaming , parts too hot for the leak test , difficult maintenance , not enough training for the maintenance people in the factory, documentation not adequate…). The  consequence : the supplier was banned for several years in the customer Factories.

The washing machines are special machines receiving the hardest working conditions in the automotive factory : aggressive detergents , agresive machining oils and coolants , chips , helical chips , flat chips , burrs , liquid temperature , full humid ambient , temperatures changes , air condensations , noise , PLC or CNC  machine tools standards , rust atmosphere… and nobody likes to maintain it ( it is a dirty job…).The machine needs a good maintenance people understanding of chemicals , electronics, mechanics , lubrication , and also “process”(wash-blow off).

To be successfully on the utilisation of a washing machine from one Continent in the other is necesary the full implication of the washer manufacturer with the customer factory engineers , and factory maintenance people (not only the customer’s purchase or staff )before the construction of the machine. Is the only way to be successfully and that the machines and the washer manufacturer can last time in the customer preferences.

Maybe the future would be that the washer manufacturer has also the responsability for the maintenance and warranty the machine performances? .I know that the are some customers looking for that.

The machine engineering of the AGULLO washers in America inspired to several american manufacturers who updated their design and technologies and incorporate to their machines some AGULLO particularities like the  robustness, mechanics or the full size guillotine door( See Valiant , HMM pictures)

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.

Part2clean Stutgart (4) Rotary transfer washers

Out of the already commented rotary transfer machines for small components , in the Parts2clean show I noted other manufacturers that they are active to wash or deburr bigger parts ( main powertrain components as cylinder block, cylinder head, crankshafts, gear box…).

Almost all the manufactures of these machines were German , and only few “foreign”. One of this foreign manufacturers was the Italian Tecnofirma. This company is an “old” company in the business. At the beginning mainly present in Italy . Years ago it started to wash cylinder block and cylinder heads Automobile components but the presence of AGULLO and ICOM in Italy stopped their development in the 1990’s . They were limited to crankshafts transfers or gear box components so long as AGULLO and ICOM had orders for the cylinder block and cylinder heads in line transfer washers for FIAT.

Tecnofirma developed rotary transfer washers for other components related to the motorcycles , tractors or gearbox components in Italy and also for the customer subsidiaries in Latinamerica or East Europe.. Now is improving his sales action in Germany and France , and they presented an interesting rotary transfer wash/deburr machine ( four stations) with an small ABB robot carrying a jet for the flex wash or blow-off.

 

 

 

 

The robot is applied directly inside of the wash chamber and has a jet on his wrist.

The High pressure pack and filter is installed in a separate module with the classic Hamelmann piston pump. The filtration is trough a safety cartridge filters and automatic paper filter

The machine has a robust look and the price announced seems interesting. Tecnofirma has a good experience in mechanical components customers. I hope that they can have a development in the next years if they achieve their export development.

Another of the “foreign” exhibitors was the Japanese SUGINO .This company has also a long history on the wash-deburr business. Their main market is the Japan companies and their transplants to other countries.

SUGINO has the best experience in high pressure applications in the wash and the deburr. Don’t forget that the Japanese automobile companies were the first ,worldwide ,to improve their cleanliness levels using high pressure water in their washers and after using also the high pressure for the deburring.This Market was advanced against the European or American markets.

SUGINOis the sole wash producer in the world, that I know ,that is also producing their high pressure pumps. In fact the division of high pressure pumps and his applications in all the industries is one of the hard points of Sugino. They have several patents and the advantage to produce themselves also the high pressure accessories ( 2ways valves, safety valves, HP jets, lances, distributors…).The use of the high pressure goes till to the jet cutting at 4.000 bars

Surprisingly despite their high experience and acknowledgement in the high pressure they have been not active in Europe. Their competitor KITO at least supplied Toyota in UK but Sugino has been out of this market. In USA they sold some machines 15 years ago in the gear box Ford factories but they din’t push too much the market and remain anecdotal.

Is really a pity because for me Sugino has experience , acknowledgement and inventive. Some tricky devices and original process invented by them ,and not yet discovered by the German suppliers( neither Americans), are fantastic and very efficient.

In the Parts2clean exhibition they presented the “Jet Clean Center”. Is a cell with CNC axis that allows to high pressure wash and high pressure deburr small components . These components can be manually load or robot load.

The must interesting thing of this machine is the Turret tool jet head. The turret has 6 possible different high pressure jets or lances that can be feeded individually trough a HP distributor. This machine is valid for small productions in a cell configuration and has been the first machine on this business to adapt the form of a High pressure cell , idea reproduced now for a lot of manufacturers.

 

SUGINO has also a family of rotary transfer machines for cylinder blocks and cylinder heads . The machine with two , three or four stations is integrated on in line or in cells productions . Recently they have supplied these machines for the new Mazda-Ford factory in China. They have a combination of the machine with a Cartesian 4 axis wash gantry robot located in the roof totally outside the machine as Durr Ecoclean Barcelona had.

The originality of their machine is that the load/unload of the parts can be made automatically without any further device .A vertical movement of the complete rotary table allows the part to be load/unload on a conveyor at the same time that the same vertical movement of the table allows to better wash and blow-off the parts in the other stations.

The application of the gantry robots instead of anthropomorphous robot in the high pressure wash-deburr applications is an interesting debate that I will write about in one further post after also a further robot cells post.

The weak point of these machines is that the indexing driving device with the vertical movement of the table is inside the machine , not easily accessible for maintenance. To do the same process the design of the Dürr Ecoclean Barcelona transfer rotary machine was much better solved with full accessibility to all the mechanics either rotary , lifting or gantry ( but more expensive of course).

In general the SUGINO wash-deburr processes , and high pressure devices are original,tricky and effective. The mechanical concept of the machine and their sizes are really designed for the Japanese Market . The design should be hardly modified to support the European rules and standards and by this reason is very difficult that some European client accept their machines standards. Is not their fault is a question of market demands. Something similar happened on the first machines supplied to Ford America.

But for markets like the Japanese or China, Korea..where the demand for big access for maintainability , and safety rules are not so stringent than in Europe , these machines are valid. But as the price is also important and these solutions are chipper, the client has to balance his decisions.

SUGINO has now a subsidiary in Chekia for his division of machine tools. It would be maybe a good opportunity for them to redesign their machines for the European Market demands.

OK ,that’s all for today. See you soon in my next post.

De-sanding / Lavado de bloques y culatas(o cabezas) de motor de automóvil después de la fundición y pre-mecanizados (cubing o Hypercubing). 1/2

Edicion en español ( English edition will be edit later)

 

Pagina 1/2

Recibo la consulta de un manufacturero de culatas y bloques motor en fundición de aluminio que desea limpiar las piezas de las virutas del mecanizado y de la arena procedente de la fundición.

Tiene dudas sobre la utilización de ultrasonidos en vez de la aspersión y alta presión para el lavado de estas piezas.  

Como este tema, es un tema que resurge repetitivamente en el tiempo entre la Industria de la Fundición de Aluminio he decidido publicar mi parecer en el Blog. Este estudio constará de varias partes que irán saliendo en días sucesivos.

 Voy a intentar ayudar en sus decisiones:

 El lavado de piezas metálicas por ultrasonidos, es un método utilizado industrialmente desde hace unos 50 años y que da buenos resultados especialmente en piezas pequeñas y con cantidades de contaminación reducidas comparadas con el peso de la pieza, asimismo los sistemas están concebidos para tiempos de ciclo de varios minutos. 

En lo que respecta al lavado de piezas de grandes dimensiones y masa tal como es el caso de culatas(cabezas) o bloques de motor, las dificultades aparecen como consecuencia de la industrialización del proceso, es decir el tratar altas producciones del orden de 80 piezas / hora o superiores y con cantidades de contaminación horaria elevadas.

  

Las Instalaciones de Ultrasonidos en estas aplicaciones según mi parecer presentan varios problemas  

 

 

Ø       Calentamiento progresivo del baño de ultrasonidos.

Ø       Necesidad de rotar las piezas en inmersión en la cuba.

Ø       Acumulación de contaminación en el fondo de la cuba

Ø       Generación de ondas de frecuencia audible

Ø       Fiabilidad de los sistemas de transporte continuo.

Ø       Fiabilidad de los sistemas de carga/descarga para producción elevada.

Ø       Alta energía instalada.

Ø       Imposibilidad de control automático de la eficiencia de los transductores

 

Veamos uno a uno estos problemas: 

1) Calentamiento progresivo del baño.

Para el funcionamiento de la limpieza con  ultrasonidos es necesario que el baño de lavado esté caliente y por lo tanto es necesario calentar el baño hasta una temperatura determinada a partir de la cual se tiene el efecto limpiador de la  cavitación.

Sin embargo esta temperatura tiende a aumentar con el funcionamiento de la máquina.

Esto se produce debido a que la energía necesaria para generar los ultrasonidos que hacen entrar en vibración la pieza a lavar se transforma en calor (ley de Joule) y teniendo en cuenta que la energía es proporcional a la masa de las piezas y a la producción, cuanta más masa o producción se tenga más energía se necesitará y más calor se generará en el baño.

Las piezas que se lavan absorben una parte de este calentamiento calentándose ellas mismas pero si la producción es elevada no es suficiente y los baños tienden a aumentar de temperatura.

Evidentemente hay soluciones diversas para resolver este problema pero todas tienen sus inconvenientes.

Si se aumenta el volumen del baño, para tener la misma intensidad de energía ultrasónica (Watios/litro) como hay más liquido, hay más volumen y masa, y por lo tanto es necesario aumentar la potencia de ultrasonidos con lo que el problema subsiste.

Si se instala un intercambiador de calor en el baño, aparte de aumentar la masa del mismo, el intercambiador sufre las consecuencias de los ultrasonidos con lo que su vida es corta.

La solución más simple es la de bombear el líquido a un intercambiador exterior a la cuba, pero con objeto de no distorsionar las ondas ultrasónicas, la bomba de trasvase solo puede funcionar durante el tiempo de transferencia de las piezas, con lo cual hay que hacerlo cíclicamente, perdiendo eficacia. 

 

2) Necesidad de rotar las piezas en inmersión. 

Los ultrasonidos deben tener la energía suficiente para que la energía vibrante llegue al interior de las cámaras de las piezas (cámara de agua y conductos de aceite). Por otra parte es necesario que la suciedad desprendida de las paredes de la pieza sea conducida al exterior de las cámaras y otras cavidades de la pieza, para ello es necesario una rotación de la pieza durante la inmersión en la cuba.

Frecuentemente para extraer esta suciedad desprendida por los ultrasonidos, hacia el exterior de las piezas se utilizan una o dos fases suplementarias en cubas separadas que se pueden llamar enjuagues ( “rinse “ ) y cuya función es con una corriente de liquido en forma de turbulencia o por aspersión el arrastrar la suciedad desprendida por los ultrasonidos pero que continua en el interior de las piezas.

Estas etapas de enjuague están también dotadas de rotación de las piezas.

Estas rotaciones, debido a efectuarse con la pieza en inmersión pueden crear problemas de fiabilidad y mantenimiento si la máquina es de alta producción.

Fin post 1/2

( continuará)

Wellcome

After 36 years of work in the washing , cleaning and deburring of mechanical parts for all the automotive Industry around the world ,I’m starting now a new complementary activity trough this Blog.

It has been a passion , an a very innovative world.

More than 1.000 washing problems , 1.000 special applications all around the world following the needs of better quality in the Automotive Industry .

From Spain to France at the beginning ,and after to UK, Italy, Germany, Russia, USA , Canada, Sweden, Brazil, China, Mexico …

Thousands of experiences and anecdotes helping the automotive engineers .

Now I’ll try to continue to help the new automotive engineers arriving to this strange world :

Why I have to wash the part ? ….How clean is clean ? ….Why the washers become  Machine tools? … Robotic washers?…Deburring?..

This Blog is in preparation. Hopping to meet you soon.

Juan Agullo

Cleanliness Management and Engineering

Barcelona