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Honing
Honing of piston bores in
cylinder crankcases

Honing of crankshaft
bearing bores in cylinder
blocks

Simultaneous precidor
honing of crankshaft and
camshaft bearing bore at
one work piece


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Honing

PERMAT supplies honing machines, honing tools, honing stones and diamond honing ledges.

Fixture Systems
Three fixture systems for honing have gained acceptance. They are used according to size and form of the component. Click on the image opposite to enlarge.


Applications

Automotive parts which are honed include:
Cylinder Blocks
Cylinder Liners
Compressor Cylinders
Connecting Rods, large and small end bore
Gears
Brake Cylinders
Injection Pump Parts
Hydraulic Valves

The working range of honing machines available from Permat covers bore diameters from 2 to 1500mm, with bore lengths in practice up to 1200mm. However, the main diameter range extends from 3 to 1200mm. Nearly all components can be honed, and in materials including hardened and unhardened steels, cast iron, bronze, brass, light metals, sintered metals, hard chronium, pressed materials, graphite, glass and others.

 

What is Honing?
Honing is defined as a cutting process with a multi-edge tool of bonded grain, under constant surface contact between component and tool.

It achieves improvement in the size, shape and surface finish of pre-machined components.

The rotating honing tool also carries out longitduinal movement, with a permanent change of direction.

This means the surfaces produced have a parallel cross-hatch pattern.

The honing process also comprises the expansion of honing stones or diamond ledges fitted onto the honing tool.

This means the material is cut steadily and the surface is smoothed over the entire length of a bore.

It is because of the quality of finish that honing has been used as a finishing method of piston bores in cylinder blocks by the automotive industry for many years.

Permat's experience is widespread in the field.       Back


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Honing of piston bores in cylinder crankcases
The use of honing as a quality finishing method of piston bores in cylinder blocks has been a part of the automotive industry for many years. Click on the image opposite to enlarge.

Permat-supplied machines are not only available for the honing of single cylinder blocks, but also for cost-effective series production in fully automatic transfer systems.

Illustrated as an example is a multi-spindle cylinder block transfer honing machine. It is equipped for rough, semi-finish and finish honing of 4, 5 and 6-cylinder engine blocks.

The spindles are shifted twice in the honing station by means of an automatic spindle shuttle device. Spindles 1 and 2 are for rough honing; Spindles 3 and 4, each with double expansion, are for plateau base honing and plateau finish honing.        Back



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Honing of crankshaft bearing bores in cylinder blocks
The need for critical levels of accuracy in crankshaft bearing bores has made precidor honing especially suitable for this automotive machining task. Precidor honing of crankshaft bearing bores can be carried out by one or two spindles. Click on the image opposite to enlarge.

Vertical machining - one or two spindles
With 1-spindlle machining up to 0.04 to 0.06mm of material (of the bore diameter) is removed, in one stroke.

With 2-spindle machining, the process is split in a rough and a finish honing operation. In the rough honing operation 0.04 to 0.05mm of the material is removed, and in the finish honing operation 0.01 to 0.02mm. The 2-spindle operation gives additional improvements in the diameter tolerance, cylindricity and straightness of the bore.

In the 2-spindle process, the rough honing operation can also be carried out using long multi-stick honing tools. This is often used when 0.098 to 0.12mm of material needs to be removed.

Horizontal machining
This machining option is especially suitable for aluminium cylinder blocks with cast iron bearing cups - i.e. when the bearing bores consist of two materials with different hardness.

The machine allows a set amount of material to be removed from the cast iron and the aluminium parts of the bore, using expandable guides in front of and behind the cutting layer of the honing tool to maintain accuracy. Click on the image opposite to enlarge.  Back




 

Permat Machines Limited
Station Road, Coleshill, Birmingham
England B46 1JG
Tel: +44 01675 463351   Fax: 01675 465816
Telex: 336040

Nagel Maschinen-und
Werkzeugfabric GmbH
P.O. Box 1709 D-7440 Nurtingen
Tel: 07022 605-0   Telex: 7267337

Simultaneous precidor honing of crankshaft and camshaft bearing bore at one work piece
Permat also supplies machaines which allow for simultaneous precidor honing of crankshaft and camshaft bearing bores. Even with large in-line and V-engine blocks of trucks, the crankshaft bearing bore is machined with a precidor honing tool. This machining process is applied both for new engine blocks as well as for repair work with reconditioned bearing cups. Of special interest is the fact that even with reset bearing cups the precidor honing tools with their multiple cutting layers generate excellent roundness and coaxiality values by only one stroke.

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