www.etopwireharness.com
A cable harness, also known as a wire harness, cable
assembly, wiring
assembly or wiring
loom, is an assembly of cables or wires which transmit signals or electrical power. The cables
are bound together by straps,cable ties, cable lacing, sleeves,electrical tape, corrugated tube, a weave of
extruded string, or a combination thereof.
Commonly
used in automobiles, as well as
construction machinery, cable harnesses provide several advantages over
loose
wires and cables. For example, many aircraft, automobiles and spacecraft
contain many masses of wires which would stretch over several kilometers
if
fully extended. By binding the many wires and cables into a cable
harness, the
wires and cables can be better secured against the adverse effects of
vibrations, abrasions, and moisture. By constricting the wires into a
non-flexing bundle, usage of space is optimized, and the risk of a short
is decreased. Since the installer has only one harness
to install (as opposed to multiple wires), installation time is
decreased and
the process can be easily standardized. Binding the wires into a
flame-retardant sleeve also lowers the risk of electrical fires.
Production
Cable harnesses are usually designed according to
geometric and electrical requirements. A diagram is then provided (either on
paper or on a monitor) for the assembly preparation and assembly.
Wire size in AWG and mm:
Crimped terminal can be analized by section-analysis machine as below photo.
The wires are first cut to the desired length, usually
using a special wire-cutting machine. The wires may also be printed on by a
special machine during the cutting process or on a separate machine. After
this, the ends of the wires are stripped to expose the metal (or core) of the wires, which are fitted with any required terminals or connector housings. The
cables are assembled and clamped together on a special workbench, or onto a pin
board (assembly board), according to the design specification, to form
the cable harness. After fitting any protective sleeves, conduit, or extruded
yarn, the harness is either fitted directly in the vehicle or shipped.
In spite of increasing automation, in general, cable harnesses continue to be manufactured by hand, due to the many different
processes involved, such as:
·
routing
wires through sleeves,
·
taping
with fabric tape, in particular on branch outs from wire strands,
· Crimping terminals onto wires, particularly for so-called multiple
crimps (more
than one wire into one terminal),
·
inserting
one sleeve into another,
·
fastening
strands with tape, clamps or cable ties.
Pre-production can be automated in part. This affects:
·
Cutting
individual wires (cutting machine),
·
crimping
terminals onto one or both sides of the wire,
·
partial
plugging of wires prefitted with terminals into connector housings,
· Soldering of wire ends (solder machine)
· Twisting wires.
Testing the electrical functionality of a cable harness
can be done with the aid of a test board, The circuit diagram data are pre-programmed into the test board, where
harnesses can be tested individually or in multiple numbers.
