13-02-2013, 04:18 PM
Pneumatic, PLC Controlled, Automotive Gear Shifting Mechanism
Pneumatic, PLC Controlled, .pdf (Size: 523.28 KB / Downloads: 109)
Abstract:
In this study, a gear shifting mechanism was designed and applied to make the shifting process faster
and less destructible for the driver. The new device must be reliable, has a small dimensions, low construction
and maintenance cost. This paper aims to improve gear shifting process using devices as: a manual four speed
gear box, four pneumatic double acting cylinders, four pneumatic two position five ways directional control
valves, Programmable Logic Controller (PLC) LOGO unit, an electrical motor, an electrical clutch, a belt, two
pulleys, limit switches, push buttons, bulbs, a table (holder) and power supply. According to suggested gear_
shifting method the driver can select the transmission gear ratio without moving his hands from the steering
wheel by putting the gear shifting push buttons on the steering wheel. Using this method leaves to the driver
the excitement of choosing the shifting moment.
INTRODUCTION
This study describes in detail in an understandable
way to how to convert the traditional manually gear
shifting mechanism to a semi-automated gear shifting
mechanism by using the Programmable Logic Controller
(PLC).
Increasing demands on performance, quality and cost
are the main challenge for today's automotive industry, in
an environment where every movement, component and
every assembly operation must be immediately and
automatically recorded, checked and documented for
maximum efficiency.
Automotive technology has been developed in many
areas, like ABS system, active steering system and other
safety systems, which are implemented to increase the
passenger safety and comfort. The development has
concluded also the gearbox, which became much
smoother and produces less noise. Gear shifting
mechanism must be easy to use and workable, these
demands are very important especially for small cars used
by special needs people.
Components description:
The holder: The holder is made of cast iron. It consists of
two groups, fixed one and movable one. The fixed group
is the lower one. It holds the batteries (electrical source),
the gearbox, the limit switches, the sliding cylinders and
the electrical motor. The movable group is the upper one.
It holds the PLC control unit, the buttons and indication
lamps board, directional control valves and front and rear
motion cylinders.
RESULTS AND DISCUSSION
Operation sequence:
Neutral position: In this position all controller outputs
are zeros. Cylinders I and III are extended and cylinder II
and IV are retracted.
Pressing the neutral button at any engaged gear the
controller outputs will be changed to zeros. Also in any
gearshift procedure the controller puts the gear in the
neutral position first and then engages the desired one, as
shown in Table 1 and 2. Table 1 describes the
inputs;Table 2 describes the outputs for the neutral
position. The directional control valves situations are
shown in Table 3.
CONCLUSION
C According to the achieved results, the suggested
mechanism is realizable and workable.
C Using the simplest PLC and required hardware
enables to convert the old traditional gear shifting
mechanism to semi utomatic one.
C The application of this mechanism leads to make the
driving process easier, reduces the risk of
destabilizing the car, the lap/stage time, and the
chance of miss shifting.