Chery A series. Manual — part 70

STEERING SYSTEM

INTRODUCTION OF STEERING SYSTEM . . … . … . … . … N-2

INTRODUCTION OF STRUCTURE . … . . … . . … . N-2

WORKING PRINCIPLE … . … … . . … . … … . . …N-3

INTRODUCTION OF PERFORMANCE … … . . … . . … . N-4

REMOVAL/INSTALLATION OF STEERING COLUMN . . … . …N-5

REMOVAL/INSTALLATION AND CHECK OF STEERING GEAR . . …N-6

REMOVAL/INSTALLATION AND REPAIR OF MAIN BODY OF STEERING

GEAR . … … . … . … . . … . … . … . . N-7

CHECK OF STEERING SYSTEM . . … . … … . . … …N-18

REGULAR INSPECTION . … . … . … . … . … . … …N-18

CHECK OF THE SEAL OF POWER STEERING SYSTEM . … . … …N-19

CHECK AND REPLACEMENT OF THE HYDRAULIC POWER OIL… . … N-20

EXHUAST OF THE STEERING HYDRALIC SYSTEM … . … . … …N-20

CHECK OF THE OUTPUT PRESSURE OF POWER STEERING PUMP … …N-21

CHECK OF THE TENSION OF THE BELT… . . … . … . … …N-21

DIAGNOSIS AND TROUBLESHOOTING OF POWER STEERING SYSTEM … N-22

PRECAUTION OF STEERING SYSTEM MAINTENANCE … . . …N-26

N-1

INTRODUCTION OF STEERING SYSTEM

INTRODUCTION OF STRUCTURE

The structure of the Power Steering System is shown as Figure 1:

he rack & pinion power steering gear is composed of three sections: control valve,

ol Valve

is a normally open rotary valve and consisted of: torsion bar1, input shaft

※

sm is rack & pinion pattern and composed of three

※

etallic hull, which is divided into right and left oil chambers by the

Figure

1

Power Steering Gear

Steering Hose

Steering Oil Reservoir

Steering Oil Pump

T
mechanical steering gear and servo cylinder. The control valve is widely utilized overseas due
to its advanced structure and high sensitivity. The mechanical steering gear is rack & pinion
pattern.

※Contr

·The control valve

2, valve bush 3 and other components. The hydraulic oil flows into the left and right oil
chambers through the pre-opened clearance of the input shaft 2 and the valve bush 3. The
structure is shown as Figure 2.

Mechanical Steering Mechanism

·The mechanical steering mechani

sections: pinion shaft, steering rack piston assy and steering link.

Servo Cylinder

·The servo cylinder has m

inner rack piston and connected with the two oil inlets of control valve.

N-2

1. Torsion Bar

2. Input Shaft

3. Valve Bush

Figure 2

To Left Chamber

Oil Inlet

To

Right Chamber

Return oil inlet

WORKING PRINCIPLE

Middle Position

·When the vehicle moves straight (the steering wheel does not turn), the hydraulic oil

which is supplied by the oil pump enters the oil inlet through the pre-opened
clearance of the rotary valve. As the rotary valve keeps immovable, the hydraulic oil
flows back to the oil reservoir from the return oil inlet. No power is produced
because the oil pressures of the two chambers of the steering gear are same.

Steering Process

·When the steering wheel turns, the clearance of the valve spool between the valve

bush and the input shaft will be changed, so the hydraulic oil which flows to the two
oil chambers forms the oil pressure difference. This difference acts on the piston and
pushes it to overcome the steering resistance and make movements. Therefore, the
steering link assy is moved to realize power steering.

Return Process

·Once the steering is completed, the force on the steering wheel will disappear. As the

effect of the torsion bar elasticity, the input shaft returns to the relative balance
position of the valve bush and the oil pressure difference between the two oil
chambers of the steering gear follows to disappear. And then the vehicle will convert
to straight-line motion by the effect of the vehicle self aligning torque of the front
wheels until it enters the straight-line position.

Road Sense Effect

·The road sense effect is also called the ability of feeling steering. The driver applies

the force on the steering wheel, which also act on the torsion bar of the steering gear
and makes it deform. The amount of deformation which increases as the steering
resistance grows, depends on the wheel steering resistance. Therefore, the driver can
judge the variation of the steering resistance by the force applied on the steering
wheel to obtain the road sense effect.

N-3

INTRODUCTION OF PERFORMANCE

※The steering force of the steering wheel can be decreased. Power can be felt obviously,

especially when the vehicle turns on spot or turns with great corner at low-speed.

※The steering sensitivity is enhanced.

※The impact of kickback from ground on the steering wheel is reduced.

※In the case of tire burst, the sudden turning of the wheels can be effectively avoided. So the

security of driving can be improved.

※The load on the steering wheel is permitted to increase, which can improve the freedom

motion of the general arrangement.

The power steering gear of the steering system of A15LHD is a standard feature, and the
mechanical steering gear is optional.

In fact, the power steering gear of A15LHD is based on the mechanical rack & pinion
steering gear and enhanced with a set of power mechanism which is composed of the engine
used as energy sources, the steering oil pump, the steering control valve, the power oil
cylinder and other components. Under the working condition, the power of the engine drives
the steering oil pump through the ribbed belt. The power steering fluid (ATF oil) is suck out
from the oil reservoir by the steering oil pump and formed pressure oil to get into the control
valve. After distributed by the control valve, the pressure oil enters the power cylinder to
push the working piston which is connected with one end of the steering rack. So the steering
power can be formed by the pressure oil through the working piston.

If the power steering system is in failure, the steering of the vehicle can be also completed by
the driver.

The optional mechanical steering gear is a rack & pinion steering gear which the power
source is the physical force (strength of the hand) of the driver. All the dynamic components
are mechanical.

N-4