Function Of Grinding Machine? - SKengineers
FUNCTION OF GRINDING MACHINE?
A grinding machine, often shortened to grinder, is one of
power tools or machine tools used for grinding. It is a type of machining using
an abrasive wheel as the cutting tool. Each grain of abrasive on the wheel's
surface cuts a small chip from the workpiece via shear deformation.
Grinding is used to finish workpieces that must show high
surface quality (e.g., low surface roughness) and high accuracy of shape and
dimension. As the accuracy in dimensions in grinding is of the order of
0.000025 mm, in most applications it tends to be a finishing operation and
removes comparatively little metal, about 0.25 to 0.50 mm depth. However, there
are some roughing applications in which grinding removes high volumes of metal
quite rapidly. Thus, grinding is a diverse field.
What is hand grinder machine?
One of the most essential hand tools is probably an angle grinder. This versatile tool can be used for various purposes, including auto repair jobs and DIY projects. They are basically used for cutting, grinding, polishing, sanding and sharpening purposes.
Types -
A surface grinder.
A cylindrical grinder.
These machines include the -
Belt grinder, which is usually used as a machining method to
process metals and other materials, with the aid of coated abrasives. Analogous
to a belt sander (which itself is often used for wood but sometimes metal).
Belt grinding is a versatile process suitable for all kind of applications,
including finishing, deburring, and stock removal.
Bench grinder, which usually has two wheels of different
grain sizes for roughing and finishing operations and is secured to a workbench
or floor stand. Its uses include shaping tool bits or various tools that need
to be made or repaired. Bench grinders are manually operated.
Cylindrical grinder, which includes both the types that use
centers and the center less types. A cylindrical grinder may have multiple
grinding wheels. The work piece is rotated and fed past the wheel(s) to form a
cylinder. It is used to make precision rods, tubes, bearing races, bushings,
and many other parts.
Surface grinder, which has a head that is lowered to a work
piece, which is moved back and forth under the grinding wheel on a table that
typically has a controllable permanent magnet (magnetic chuck) for use with
magnetic stock (especially ferrous stock) but can have a vacuum chuck or other
fixture means. The most common surface grinders have a grinding wheel rotating
on a horizontal axis cutting around the circumference of the grinding wheel.
Rotary surface grinders, commonly known as "Blanchard" style
grinders, have a grinding head which rotates the grinding wheel on a vertical
axis cutting on the end face of the grinding wheel, while a table rotates the
work piece in the opposite direction underneath. This type of machine removes
large amounts of material and grinds flat surfaces with noted spiral grind
marks. It can also be used to make and sharpen metal stamping die sets, flat
shear blades, fixture bases or any flat and parallel surfaces. Surface grinders
can be manually operated or have CNC controls.
Tool and cutter grinder, which usually can perform the minor
function of the drill bit grinder, or other specialist toolroom grinding
operations.
Jig grinder, which as the name implies, has a variety of
uses when finishing jigs, dies, and fixtures. Its primary function is in the
realm of grinding holes for drill bushings and grinding pins. It can also be
used for complex surface grinding to finish work started on a mill.
Gear grinder, which is usually employed as the final
machining process when manufacturing a high-precision gear. The primary
function of these machines is to remove the remaining few thousandths of an
inch of material left by other manufacturing methods (such as gashing or
hobbing).
Centre
Grinding Machine -
Centre grinder, which is usually employed as a machining
process when manufacturing all kinds of high-precision shafts. The primary
function of these machines is to grind the centers of a shaft very precisely.
Accurate round center holes on both sides ensure a position with high repeat
accuracy on the live centers.
Die grinder, which is a high-speed hand-held rotary tool
with a small diameter grinding bit. They are typically air driven (using
compressed air), but can be driven with a small electric motor directly or via
a flexible shaft.
Angle grinder, another handheld power tool, often used in
fabrication and construction work.
Angle grinder -
An angle grinder, also known as a side grinder or disc
grinder, is a handheld power tool used for grinding (abrasive cutting) and
polishing. Although developed originally as tools for rigid abrasive discs, the
availability of an interchangeable power source has encouraged their use with a
wide variety of cutters and attachments.
Angle grinders can be powered by an electric motor or compressed
air. The motor drives a geared head at a right-angle on which is mounted an
abrasive disc or a thinner cut-off disc, either of which can be replaced when
worn. Angle grinders typically have an adjustable guard and a side-handle for
two-handed operation. Certain angle grinders, depending on their speed range,
can be used as sanders, employing a sanding disc with a backing pad or disc.
The backing system is typically made of hard plastic, phenolic resin, or
medium-hard rubber depending on the amount of flexibility desired.
Uses -
Angle grinders may be used for removing excess material from
a piece. There are many different kinds of discs that are used for various
materials and tasks, such as cut-off discs (diamond blade), abrasive grinding
discs, grinding stones, sanding discs, wire brush wheels and polishing pads.
The angle grinder has large bearings to counter side forces generated during
cutting, unlike a power drill, where the force is axial.
Angle grinders are widely used in metalworking and
construction, as well as in emergency rescues and bicycle theft. They are
commonly found in workshops, service garages and auto body repair shops. There
are a large variety of angle grinders to choose from when trying to find the
right one for the job. The most important factors in choosing the right grinder
are the disc size and the power of the motor. Other factors include power
source (pneumatic or electric), rpm, and arbor size. Generally disc size and
power increase together. Disc size is usually measured in inches or millimetres.
Common disc sizes for angle grinders in the United States include 4, 4.5, 5, 6,
7, 9 and 12 inches, while in Europe most common sizes for angle grinder discs
are 115 and 125 millimeters. Discs for pneumatic grinders also come much
smaller. Pneumatic grinders are generally used for lighter duty jobs where more
precision is required. This is likely because pneumatic grinders can be small
and light yet remain powerful, because they do not contain heavy copper motor
windings, while it is harder for an electric grinder to maintain adequate power
with smaller size. Electric grinders are more commonly used for larger, heavy
duty jobs. However, there are also small electric grinders and large pneumatic
grinders.
Safety -
Through a sound pressure level and vibrations study
conducted by the National Institute for Occupational Safety and Health,
grinders under an unloaded condition ranged from 91 to 103 dBA. In addition,
angle grinders produce sparks when cutting ferrous metals. They also produce
shards cutting other materials. The blades themselves may also break. This is a
great hazard to the face and eyes especially, as well as other parts of the
body, and as such, a full face shield and other protective clothing must be
worn. Angle grinders should never be used without their guard or handle
attached. All workpieces should be securely clamped or held firmly in a vise.
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