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DIAMOND DRESSING ROLLS
Introduction: what is a diamond roll
A diamond dressing roll could be considered as a multiple rotative
diamond with the purpose of forming a grinding wheel maintaining the
shape, dimensional tolerance and to allow determined workpiece finishing
grade for the all grinding operation process.
Basics factors choosing a diamond roll
Basics parameters for choosing a diamond roll are as following:
- Speed in relation of diamond roll and grinding wheel
- Speed in relation of grinding wheel and workpiece
- Diamond roll infeed
- Coolant
therefor to obtain:
- Considerable grinding reduction of dressing time
- Less grinding wheel worn out
- Insure and maintain quotations and required profile during the all
grinding operation process
- Reproduction of any profile for any particular shapes.
A diamond roll is particularly recommended for dressing operation
on automatic cycle machine tools and for high series production.
From long time the majority of machine tolls builder's, dedicated
for working particular pieces of large series, have thought of a possibility
to arrange the machine tools for using diamond dressing rolls instead
of traditional dressing system, in purpose of answering customer's
requirements, and at the same time remaining by an advanced production
tecnology, high quality products and productivity.
Production of diamond dressing rolls at
SIMAT
SIMAT Abrasivi, as all the interested on development and progression
on this field, first from the continuos customer's requirements and
than encouraged due to several tests success, have created a manufacturing
department for producing diamond dressing roll. The company achieved
a production increase, improving quality with continuous and regular
trials searching for new construction system, by advanced technologies
and less expensive products that today are the basis of competitiveness
on the European market.
Description of the two main type of dressing
operation
DRESSING BY A SINGLE DIAMOND
During this operation the diamond is cutting systematically the abrasive
grain, giving better roughness finishing grade on the workpiece: dressing
time are relatively long.
- High infeed speed ----> h i g
h roughness
- Low infeed speed ----> low roughness
DIAMOND DRESSING ROLL
Even if it could sound expensive, in practice it turned economic.
This type of tool could be considered as an effective alternative
compare to the dressing tool mentioned above: the circular shape and
the rotative motion will highly increase the tool life and to improve
product quality grinded by grinding wheel.
The very short dressing time, the quality and the profile constancy
reproduced on various pieces, and a very low scrap amount, rapidity
and simplicity on the machine tools working process will reduce cost
for each single piece.
Naturally the achievement of a diamond dressing roll efficiency is
tied with dressing parameters and type if diamonds, than functional
precision of the dressing mechanism, machine tool power and its toughness.
Production of diamond rools at SIMAT Abrasivi
There are two main type of production process for diamond dressing
rolls, sintered or infiltrated that we will identify with letter "S"
and reverse plated or galvanic that we will identify with letter "ED".
Furthermore there is a type of diamond roll produced by a combination
between sintered and reverse plated, than another type produced by
polycrystalline inserts.
Group "S": sintered or infiltrated diamond roll
Diamond roll produced by positioning the diamonds on a negative matrix,
that allowed the use of different type of diamond on the same roll
in reference of its use obtain a profile longer life.
Execution type "S"
Forming diamond dressing roll with stones set and positioned by hand
following a particular arrangement. Inverted process, metal bonded
infiltrated.
Execution type "SDS" (or "CDC") Forming diamond dressing roll with
stones set by a statistic distribution, maximum concentration, inverted
process, metal bonded infiltrated.
Execution type "SP" Forming diamond dressing roll with stones multi-layer
structure, statistic distribution of diamond with controlled concentration,
metal bonded infiltrated.
Execution type "SS" Forming diamond dressing roll with stones hand
set on parallel layers. Controlled concentration, inverted process,
metal bonded infiltrated.
Group "ED": reverse plated or galvanic
Used for diamond dressing rolls with complex shapes and profiles:
obtained by galvanic process with the use of system that controls
and maintain constant, during the cycle, all the chemical and electrical
parameters.
Execution type "ED" Diamond dressing roll with diamond positioned
by statistic distribution. Single layer, maximum concentration, galvanic
bonded and inverted process.
Execution type "EDD" Diamond dressing roll with diamond positioned
by statistic distribution. Single layer, maximum concentration, galvanic
bonded and direct process.
- Other type of diamond dressing rolls:
Execution type "SE"
Combined diamond dressing roll between "S" + "ED"
Execution type "PKD"
Routing diamond dressing roll with polycrystalline inserts. Set
and positioned by hand. Reversed process, controlled concentration,
metallic bonded infiltrated.
Other than standard diamond dressing roll producer, with natural diamond
carefully selected, SIMAT Abrasivi is manufacturing diamond dressing
roll with polycrystalline inserts, that would substitute monocrystal
diamonds.
The principal advantages using this type of tool is the extraordinary
roll life, the efficiency during dressing operation, and, as a consequence,
better performances of grinding wheel dressing for special purposes.
These inserts, called "PKD" are extremely resistant to temperature
as high as 1200°C in an non-oxide atmosphere without any thermal variation,
insuring excellent performances during these operation where the grinding
process is developing an intensive heat.
All the "PKD" inserts used by SIMAT Abrasivi are accurately selected;
the inserts are single diamonds crystals bonded together by high temperature
process any by high pressure, a process that gives extraordinary density
to all the single inserts giving toughness, strongness and wear-out
resistant.
During dressing operation the crystals with sharp edges are always
on the surface insuring efficiency and grinding wheel selfreconditioning.
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