Honda Acura NSX 1991, Service Manual

Page: 603 / 1420

System Description
*Function and Operation
Steering Sensor
The steering sensor consists of a torque sensor, an
and the rotation sensor.
BAR
INPUT
SHAFT
Torque Sensor
The torque sensor converts steering torque input and its
direction to voltage signals, in conjunction with the in-
terface.
A torsional force caused by steering operation is convert-
ed to an axial movement of a slider core. A variable
differential transformer is installed around the slider core.
Within the tranceformer are three coils, primary coil on
the inside, and two secondary coils, one for right turns
and one for left turns.
Alternating current is passed through the primary coil
when the system is energized. The amount of mutual in-
duction from the primary coil to the secondary coils
changes depending on the position of the slider coil.
The input shaft and the slider are one piece. Rotation of
the shaft moves the slider in a circular direction. The pin-
ion is turned via the torsion bar. The slider core is installed
on the pinion shaft on grooves, and turns with the pin-
ion shaft.
When there is little resistance, the input shaft tot-don bar,
pinion shaft, and the slider core turn together to the same
angle. The slider core does not move up/down.
INTERFACE
CIRCUIT
TRANSFORME
PINION GEAR
When there is resistance on the input shaft (hard to steer situation), and the slider pin is turned at an angle by the steering
wheel, the bar is twisted due to the resistance. Accordingly, the pinion shaft turns at a smaller angle. The differ-
ence in the turning angles changes the position of the slider pin in the groove, forcing the slider core upward or down-
ward, depending on the direction of the direction of the turn.
PRIMARY COIL
\
UPPER SECONDARY COIL
SLIDER
LOWER SECONDARY
D W G
Nn.
Steering condition
Slider movement Induction voltage on secondary coil
A
Steering to right
Upward shift
Voltage on upper coil increases and that on the lower
(load steering)
decreases
B
Advancing straight ahead
(no load steering)
Neutral Voltage on upper and lower coils are equal
C
Steering to left
Downward shift
Voltage on lower coil increases and that on the upper
(load steering)
decreases
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