Water jackets cleaning

One of the more difficult areas to clean in the cylinder heads and cylinder blocks of the automobile engines is the water jackets,Why?

1) The internal volumes of the water jackets are complex and very often with narrow passages. By one side the cylinder head designers wants to have a minimum water jacket volume in order that the engine can rise in temperature rapidly to have the optimum engine performance. By other side is important to refrigerate all the areas of the cylinder head , mainly around the combustion chambers , but the number of valves per cylinder create narrow passages inside the water jackets.

2) On the machining of the aluminium alloys the cutting speed are more and more elevate and create longs chips . The cycles times on the machines are more and more shorts and there is not too much time to break the chips.On the transfer lines it was easier to do than in the present CNC flexible lines.

3)As consequence of the cutting speeds and short cycle times the chips are very often pushed inside the water jackets by the final milling tools.

4) The consequence of long spring chips inside small pockets and narrow passages  is chips trapped inside the water jackets.

The cylinder head is more sensitive to this problem but some cylinder block too. Here joint you can see what you can find inside a cylinder head water jacket:

       There is a clear test : If we cut a supposed clean cylinder head in slices it will allows us to see if there are some chips trapped inside the water jacket. I’ll say that the majority of clean cylinder heads have chips inside.

Is dangerous for the engine run? Well, first you have to assembly your engine (cylinder head , cylinder block , camshafts, crankshaft..). During the automatic assemply this remaining chips can fall down of the parts and goes to the assembly machine or between the parts to be assembled blocking the operation and stopping the machine and the line.

Second if you assembly your engine with no problem but the chip remain inside , is possible than during the engine run with the vibrations and , temperature changes , the chips goes out of the water chamber and arrives to the water pump causing the failure of the water pump , heating the engine and stopping the car engine.

Another added problem is the remaining sand balls remaining inside the water jackets coming from the cast process:

 

 

 

Since many years this water jacket problem has been the major nightmare for the equipment suppliers and for the automotive industry .

The process to remove the remaining sand inside the water jackets  is called “desandind” and will be considered in a further post . today we will concentrate only in the chips removal :

Some suppliers were using a contact jet at 20/30 bars to flush inside the water jackets( ICOM, Hafroy). Or” injection flood” ( Dürr) injecting 10/15 bars jet against the waster jacket on immersion of the part . Or the “Aqua cannon”(Valiant) with a medium pressure short discharge inside the part pulsing the water inside. 

Or the High pressure ( 200 bars) target injection trough the part openings (Agullo).

Or a mixture of systems like Sugino .

In any case the problem is a difficult problem and needs test with real parts to achieve an acceptable process. Of course the automobile client is also an important part. If the cleanliness test to control the cleanliness of the cylinder head is a manual flushing of a solvent trough the part( and water jacket ) is probably than the flushing (normally at 1 to 3 bars) will not be able to remove the blocked chips inside the water jackets and the test can give a result of accepted clean part when it has trapped chips inside the water jackets.

Some cleanliness tests in the automobile have added operations to the cleanliness test procedure to verify these water jackets. One is the manual hammer percussion by the operator of the cylinder head in a certain position in order to detach the chips balls inside . I remember than years ago in an european engine manufacturer the company Hafroy supplied one transfer machine that had a pneumatic hammer in one of the Ferris wheel wash stations to reproduce the operator cleanliness test operation and try to remove this balls. I remember that the line operators call the machine the “Bell” ( a “dong” each 30 secs was not appreciated by the operators around the line).

Another system is the manual checking of the water jackets with a small  endoscope . This system is of course the more efficient but some times you can not reach all the internal areas. Only cutting the cylinder head you can really check it.

To reduce the chips and traps inside the water jackets is necessary a close work between the cylinder head designers ,cylinder head  machining engineers and the “cleaning” engineers to avoid narrow passages inside the water jackets design , to avoid big and spring chips during the machining, to have high coolant volume during the machining , or cover plates during machining . If you diminish the size of the chips , if you avoid the spring chips , if you avoid narrow passages and traps inside the water jacket , if you have more than one opening of the cylinder head water chambers you will have more opportunities to remove the inside trapped chips.

Maybe one of the Automobile manufacturers that pay more attention to the water jackets has been Fiat . In their wash process specification the request several water jacket wash operations in each of the washers of the cylinder head line. More water jacket wash operation you have with the part in different positions and injecting the water by different areas to create different flows inside the water jackets allows them to have more opportunities to remove the chips. Of course this redundant system is expensive and the present tendency in the Automotive industry is to reduce the number of washers in the lines.

In any case the miracles are impossible and if you really check inside your cylinder head water jackets(or cylinder block water jackets) you have to pay attention to the whole manufacturing process including the more effective wash processes to remove the trapped chips and to have a really clean part.

 

A good system is to collect and classify all the chips shape produced in the machining line , operation by operation .  

And then looking to the chip type remaining inside the W.J. you can identify in which machining operation the chip is produced and penetrates in the W.J. Working with the machining process engineers it comes very often the possibility to reduce the size of the chip or to eliminate the quantity remaining in the parts

 

The automobile cleanliness tests procedures are also an interesting point to be examined in a further post. They are the reason why some time one washing machines that is a good machine for an automotive manufacturer but fails in another manufacturer.

Cylinderhead Brush deburring(1)

Many components of the automobile engine are in aluminium .When the aluminium parts are machined it remain on the edges small parts of material that we call burrs.

These burrs have to be removed to avoid problems during the part assembly or for the good mechanical function of the part.

The action to remove these burrs is known as “deburring”. According with the areas where are located these burrs there are several ways to removed it in high production processes: by brush deburring , by abrasive blast , by high water jets, electrolytic, walnut shell, thermal deburring, paste deburring, vibratory bowl abrasive deburring…

The most used in the automotive  industrie for the cylinder heads are the brush deburring and the high pressure water deburring.

There are a lot of suppliers for the deburring equipments but to have a cost productive process the best solution is to include the deburring process on the wash process. Why? . Because the parts after machining or after deburing have to be washed as well and because the brush deburring with aluminum parts has to be made in wet conditions .

The brush deburring and the high pressure deburring have been the two technologies better integrated in the wash lines.

The first integrator of brush deburring in the wash lines was the company AGULLO in the late 70’s. The first machines were supplied to RENAULT in France for the deburring of aluminium cylinder heads at high production (300 p/h). The cylinder head combustion , cam and manifold faces were deburred with automatic brush deburring units located at the entrance of an in line lift and carry transfer washing machine.

The brush deburring units to increase their deburring efficiency have evolved to planetary brushes where several brushes rotated on their shaft at the same time that theirs shafts rotated around the main shaft. These planetary heads have been for many years a reference on the brush deburring having a combined action to remove the burrs of the edges.

In a cylinder head machining line there are normally three wash operations : Primary,intermediate and final . The deburring operations are incorporated generally on the intermediate and the final washers.

 In the  intermediate washer there is the brush deburring of the cylinder head camsahft face , and the complete wash of the cylinder head before the bearing cap assembly .

On the final washer the machine  incorporates the deburring of the remaining faces ( combustion , manifolds, and extremities faces) . According with the production rate and the number of faces to be debured  the final washers became big machines (till  13 mts. long) and the PLC softwares complex. For these reason it was a tendency in late 80’s to separate this last brush deburring operation of the final wash operation in two machines: one machine for deburring with brushes and one for high pressure final wash-deburr.

The cylinder heads had more and more areas to deburr and the final cylinder head deburring became a self transfer complete machine.

 

Late 80’s the high pressure water deburring was also applied in high production cylinder heads . The first high production machine in Europe was supplied by AGULLO in Ford UK with 600 HP power and four high pressure pumps.

The high pressure water deburring can deburr faces but also has the advantage to allow to deburr oil galleries intersections and in the final washers the high pressure wash become also a standard to allow high cleanliness levels . In consequence the high pressure deburr is used in the final washers as a complement of the final wash operation.Having then the high pressure pack on the final washer why not to use the HP water for a complete deburring of the cylinder head? 

Of course this could be an option but the operational cost of a high pressure deburring operation is 2 to 3 times more expensive that for the brush deburring . In consequence anything that can be effectively brush deburred is better to do it with brushes than with high pressure water.

In the present the aluminum cylinderheads or the aluminium cylinder block flat faces are preferably deburred with brushes keeping the high pressure water for the oil galleries intersections , or other small deburring operations (oil galleries , bearing cap intersections, oil feed…)

 For a new part project ( i.e. cylinderhead) is possible to identify areas where the burrs will be present after machining and that have to be removed. But you can not identify 100% of the areas .Some times due to machined areas intersections with cast areas the burrs are present but not  in an predefined position .For this reason is useful on the cylinder head final washers to have a high pressure water jet programable with CNC or robotic  and a reserve of several seconds on the cycle time to can solve these unexpected burrs .

The brush deburring for flat surfaces is the more cost efficient solution compared with the high pressure water , but the high pressure water can reach areas where the brushes can’t.

Now in the market there are several companies proposing the planetary brush deburring heads .

The recommended brushes are the cups with stainless steel wire , but for certain aluminium the abrasive wire is also wellcome.

In  next post we will explain how to manage the brush wire wear compensation.

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.

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.

 

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)2/2

(Edición en español)(English versión will be edited later) .

Pagina2

 

 

 Continuo con el examen de los puntos problemáticos indicados en mi anterior Post.

 

3) Acumulación de contaminación en el fondo de la cuba. 

Se produce por el propio efecto que se busca, es decir la eliminación de la contaminación de las piezas, la cual queda depositada en el fondo de la cuba de lavado por ultrasonidos.

La contaminación como la energía, es proporcional a la producción y las dificultades para eliminarla es considerable.

Además hay que tener en cuenta que cuanta más contaminación hay en el baño, mas energía se necesita para el lavado de las piezas ya que parte de la misma se deriva para el “lavado” de la contaminación depositada en la cuba.

Hay también diversos métodos para eliminar la contaminación del fondo de la cuba, pero ninguno de ellos da una satisfacción completa.

La utilización de transportadores dragantes, aumenta la masa a poner en vibración y al mismo tiempo el paso de las palas de la draga provoca distorsiones en las ondas ultrasónicas, lo que crea frecuencias audibles que aparte  de ser muy molestas, pueden fácilmente aumentar el nivel de ruido permitido en el edificio donde se ubica la máquina, creando en consecuencia la necesidad de insonorizar abundantemente la máquina.

El utilizar una bomba para la filtración en derivación del baño, crea además de los problemas expuestos anteriormente para la bomba de refrigeración, la dificultad de que no se puede garantizar la filtración de la totalidad del líquido con lo que siempre queda una contaminación residual en suspensión en el baño, que en determinadas circunstancias puede contaminar una pieza considerada limpia.

Cuando la pieza salga del baño puede volver a ser contaminada con la suciedad en suspensión en el baño.

La filtración no es un filtración en línea sino sólo una filtración en paralelo o derivación.

 

4) Generación de ondas de frecuencia audible.

Debido a que los ultrasonidos utilizan frecuencias próximas al umbral audible, los armónicos de estas frecuencias entran el campo de frecuencias audibles, siendo este fenómeno más acusado a medida que se aumenta la potencia del generador de ultrasonidos.

Este fenómeno que es sobradamente conocido por los especialistas, obliga a insonorizar los equipos con las consiguientes consecuencias de dificultad en la accesibilidad a los equipos.

Si debido a la masa y cantidad de piezas a lavar, la instalación necesita de una alta potencia de ultrasonidos, necesita en consecuencia una insonorización muy completa, con el consiguiente coste de inversión y superficie utilizada.

Hay que construir una “caja insonorizante “ completa alrededor de la maquina.

 5) Fiabilidad de los sistemas de transporte continuo

Las maquinas de lavado de pequeñas piezas trabajan habitualmente con las piezas en cestas y lo que se manipulan son cestas .Para pequeñas producciones se pueden utilizar entonces manipuladores, “gantry” o rodillos  para automatizar las cargas y descargas. pero para altas producciones los sistemas mas utilizados son los de cadena “pater noster” que trasladan y sumergen las piezas en las cubas en continuo . Estos transportadores tienen problemas ya que son de elevada longitud , no son precisos y se estiran con el tiempo 

 

6) Fiabilidad de los sistemas de carga/descarga para producción elevada 

Para las producciónes habituales de unas 100 piezas / hora es necesario cargar como mínimo 2 piezas en cada carga para tener un mínimo mayor a 1 minuto de tratamiento . Como el sistema de transporte no es preciso y la pieza no está totalmente mecanizada, el método de carga y descarga debe ser empujando las piezas en la carga y extrayéndolas en la descarga, guiándolas lateralmente. Este sistema tiene forzosamente juegos mecánicos para que pueda funcionar y ello produce inevitablemente atascos y averías. 

7) Alta energía instalada.

Es evidente que una instalación para el desarenado de piezas de motor a una cadencia de 100 piezas por hora o más necesita una gran cantidad de energía  en una maquina de ultrasonidos teniendo en cuenta la necesidad de potencia para los ultrasonidos , la calefacción necesaria , las bombas de filtración , transportadores y eventual refrigeración de los baños . que aplicada de otra manera, por ejemplo con agua a alta presión, produce los mismos o mejores resultados sin tener que soportar los inconvenientes mencionados anteriormente. 

 

8) Imposibilidad de control automático de la eficiencia de los transductores de ultrasonidos.

Las ondas de ultrasonidos en los baños  de lavado son creadas por unos “Generadores de Ultrasonidos “ o unidades de potencia situadas en el armario eléctrico de la máquina o en un armario aparte , que generan unas ondas eléctricas convertidas en ondas ultrasonoras por unas placas que se sumergen en el baño de lavado . Estas placas se llaman “Transductores” y pueden ser planos o tubulares en función de la potencia a transmitir .

Los transductores sumergidos en el liquido generan las ondas ultrasónicas que van a alcanzar las piezas que se introduzcan en los baños.

Sin embargo para el control del proceso es fácil el controlar eléctricamente que el generador funcione pero no es tan fácil controlar que el transductor en la cuba genere las ondas a pleno rendimiento . Estos transductores pierden eficacia con el tiempo y es necesario el cambiarlos periódicamente .

Para controlar su eficiencia durante los últimos 50 años se ha intentado encontrar algún sistema que permitiera el control en automático de su eficacia del mismo modo que por ejemplo se controla la presión  de una bomba con un manómetro .

Sin embargo hasta ahora no parece que haya sido posible encontrarlo y el único método fiable sigue siendo el de sumergir en el baño una fina hoja de papel metálico que debido al efecto de las ondas de ultrasonidos se produce una cavitación en la superficie de la hoja y la misma se micro perfora .

Comparando el numero de perforaciones en la hoja de metal con un  transductor nuevo con el numero de perforaciones obtenidas en una hoja similar pero con el transductor que queremos controlar podemos evaluar su estado .

Como se entiende este sistema para máquinas de gran producción es muy engorroso y poco práctico. Por ello se considera uno de los problemas típicos de mantenimiento  de estas maquinas al no poderse controlar en automático.

 

CONCLUSIONES

Por todas estas razones consideramos que si bien el sistema de lavado con ultrasonidos es un sistema que funciona bien tanto con agua como con solventes o hidrocarburos para pequeñas piezas o pequeñas producciones es una técnica que en la aplicación de desarenado y alta producción necesita de un gran mantenimiento , superficie ocupada ,potencia instalada y bajo rendimiento ,con una dificultad grave de no poder controlar la calidad del proceso de un modo automático y por lo tanto desaconseja su utilización en el desarenado a alta producción .

 

 

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