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.

Parts2clean Stuttgart (3) Rotary transfer washers

One of my former customers , ask me why I have not talk about his Dürr Ecoclean rotary transfer washing machines in my last post.

Sorry¡¡¡ ,  effectively I supplied when I was in Dür Ecoclean an installation with three excellent rotary transfer washers to clean common rail injection pumps components at 2.000/300 bars that are today working 24h a day without problems.

The installation had a previous stage of high pressure deburr with robot at 2.000 bars followed of a rotary transfer machine with medium pressure spray wash,high pressure wash(300bar) with injection in contact and push pull system, spray , blow-off , vacuum dry . These machines are the top range in the field with central filtration and high pressures power units.The machines were designed and engineered by the Barcelona Dürr Ecoclean office team that was closed in 2007 but I’m not sure that these type of machines are still part of the Dürr Ecoclean catalogue. For this reason a I didn’t mention it in my last post that was dedicated mainly to the Parts2clean presentations.

Another innovative advantage of these machines was the flexibility as easy reconversion for new different parts. The pallet support on the rotary transfer table was of a quick change design. The clamping and High Pressure injection devices were of quick reconversion. The high pressure robot deburr( 2.000 bar operation) had automatic gripper change device with automatic grippers storage .

As maintenance features they had: total index driving system accessibility, total open doors for inside accessibility , quick change of internal components. The Centralised tank , filtration ,medium pressure pumps ,high pressure pumps ,very high pressure pumps , water treatment, and safety filters were installed in a remote area allowing to deserve three or more rotary transfer machines. This layout allowed to have a minimum surface layout on the working areas occupied by the machines itself , keeping the bigger floor surface of the tanks and pumps in the remote area . By other side this layout was an advantage for the maintenance people having all the pumps, valves,and filters in the same area for easy control and follow up..   

Neverless there is another type of Rotary transfer machines , the machines for powertrain components like cylinder blocks and cylinder heads by one side , and another simpler machines for gearboxes and crankshaft .

In my next post we will talk of the cylinder block and cylinder head rotary transfer machines.