Mild Hybrid
Mild Hybrid is a compact hybrid system that improves fuel efficiency by utilizing the energy during deceleration.
Fuel
efficiency
is
improved
by
storing
the
energy
from
deceleration
in
the
battery
and
then
using
that
energy
when
the
vehicle
idling
stops
or
is
accelerating.
Mild
hybrid
also
smoothly
restarts
the
engine
after
an
idling
stop.
Due
to
its
compact
unit
size,
Mild
Hybrid
can
be
installed
in
a
wide
range
of
vehicles.
System Operation
[When Decelerating]
The energy when decelerating is regenerated and stored in the battery.
[When Stopped]
When
the
vehicle
is
stopped
by
stepping
on
the
brake,
the
idling
stop
function
is
activated,
and
the
electricity
stored
in
the
battery
is
used
for
the
electrical
equipment
in
the
vehicle,
enabling
a
long-duration
idling
stop.
When
the
brake
is
released,
the
engine
smoothly
restarts.
[When Accelerating]
In addition to the engine, electricity stored in the battery also drives the motor to assist acceleration.
These
functions
improve
fuel
efficiency.
Some
models
are
equipped
with
a
lithium-ion
battery
to
regenerate
more
energy
when
decelerating.
These
vehicles
will
begin
idling
stop
during
the
deceleration
and
extend
the
idling
stop
time.
Furthermore,
the
lithium-ion
battery
contributes
to
even
greater
fuel
efficiency
improvements
by
increasing
the
amount
of
assist
during
acceleration.
System Mechanism
The ECO Motor (Energy Control Motor) plays a central role in Mild Hybrid. The ECO Motor combines the starter function to start the engine, the generator function to generate electricity, and the drive assist function. In addition, it has two batteries installed to store electricity, a normal battery and a battery for Mild Hybrid.
[When Decelerating]
When decelerating, the ECO Motor regenerates the energy from deceleration and charges the two batteries.
[When Restarting from an Idling Stop]
When
the
vehicle
is
stopped,
the
engine
stops,
the
idling
stop
state
is
set,
and
the
vehicle's
electrical
equipment
is
driven
by
the
electricity
stored
in
the
batteries.
When
the
engine
is
restarted,
the
two
battery
systems
are
separated,
with
one
battery
powering
the
ECO
Motor
to
restart
and
the
other
battery
powering
the
electrical
equipment.
As
a
result
of
this,
stable
power
is
always
being
supplied
to
the
electrical
equipment.
The
ECO
Motor
is
always
connected
to
the
crankshaft
via
a
belt,
thereby
providing
a
quieter
and
smoother
engine
start
than
a
conventional
gear
reduction
starter.
Additionally,
two
sensors
detect
the
crank
angle
with
a
high
degree
of
accuracy
and
fuel
injection
timing
is
precisely
controlled
so
that
the
engine
can
be
started
quickly.
[When Accelerating]
The ECO Motor provides torque assist from the electricity in the batteries to reduce engine load.
Some models are equipped with a lithium-ion battery for Mild Hybrid. With the superior charge/discharge performance of lithium-ion batteries, these vehicles can extend the idling stop time by increasing the amount of energy regenerated when decelerating and can also increase the amount of torque assist during acceleration.