SANY Crawler Hydraulic Excavator (SY195C9, SY205C9, SY215C9, SY225C9). Shop Manual (2013)

Structure and Function

4.9.3 Engine and pump composite control function

PPC valve

Operator cab

Monitor

Travel

MAX

Boom UP/DOWN

Arm IN/OUT

Bucket DIG/DUMP

Swing

MIN

Fuel control dial

MC Controller input

Pressure

Option pressure

H/S/L/B

sensor

Auto-idle cancel

Travel speed swithing

Alarm output

Main control valve

Pressure

Engine chamber

sensor

KC controller

Engine

Oil-feed

Pump

adjustment

Pump proportional

pressure reduce

solenoid valve

Throttle motor

Potentio-

Motor

meter

R. Pump control angle

F. Pump control angle

Engine speed

Calibrator

LED

Actual throttle position feedback

MEMORYON

A/I

Control motor

LED

DOWN

RPW

LED

PWR resouce DC24V

A/I

Fuel, coolant temp and others

(Battery)

ZX215-1002186

4-170

Structure and Function

Function

Ɣ This function allows the operator to select

a working mode according to the job to

be performed and change engine power

output. Four different working modes are

available: H, S, L and B. To select a work-

ing mode, use the working mode selector

switch on the machine monitor.

Ɣ The main controller controls the pump so

that it can absorb all the torque at the out-

put points of the engine depending on the

pump absorption torque specified for each

Engine speed N

mode, rotation set by the fuel control dial,

ZX215-1002193

and actual engine speed.

Specifications

H mode

Engine

~1600

1600~1800

1800~2250

speed

Power (KW)

115

S mode

Engine

~1600

1600~2250

speed

Engine speed N

ZX215-1002194

Power (KW)

L mode

Engine

~2250

speed

Power (KW)

Pump output pressure P

ZX215-1002195

4-171

Structure and Function

Control method of each working mode

H mode

Ɣ The matching point of H mode: rated

speed 114kW/2050rpm

Ɣ If pump load increases and pump pressure

rises, engine speed drops. In this case,

engine speed will rise to near the match-

ing point, allowing the pump controller to

reduce pump discharge. On the contrary, if

pump load decreases and pump pressure

Engine speed N

drops, pump controller will continue to in-

crease pump discharge until engine speed

ZX215-1002190

reaches the matching point.

Engine speed N

ZX215-1002191

Pump output pressure P

ZX215-1002192

4-172

Structure and Function

S mode/B mode/L mode

Power output rate of at each working mode

Mode

Power output rate

90%

80%

70%

Ɣ At this time, the controller keeps the pump

oil-suction torque in line with the stabling

motor curve, and controls engine speed

Engine speed N

through combined control of the engine

and pump.

ZX215-1002193

Engine speed N

ZX215-1002194

Pump output pressure P

ZX215-1002195

4-173

Structure and Function

4.9.4 Pump control function

Main

Press.sensor

Engine

pump

Fuel injection

Throttle

pump

motor

Speed

Servo

sensor

Proportional

valve

Fuel control dial

Monitor

Controller

(CAN bus)

ZX215-1002196

4-174

Structure and Function

4.9.4.1 Electrical positive flow control

Pump 1

delivery

amount

Boom RAISE PPC pressure

Pump 1

delivery

amount

Arm IN PPC pressure

Pump 1

delivery

amount

Arm OUT PPC pressure

Pump 1

delivery

Corresponding

amount

delivery output

MAX

Bucket CURL PPC pressure

Pump 1

delivery

amount

Bucket DUMP PPC pressure

Pump 1

delivery

amount

Swing PPC pressure

Pump 1

delivery

amount

L. Travel PPC pressure

ZX215-1002197

4-175

Structure and Function

Pump 2

delivery

amount

Boom RAISE PPC pressure

Pump 2

delivery

amount

Arm IN PPC pressure

Pump 2

delivery

amount

Arm OUT PPC pressure

Pump 2

delivery

Corresponding

amount

delivery output

MAX

Bucket CURL PPC pressure

Pump 2

delivery

amount

Bucket DUMP PPC pressure

Pump 2

delivery

amount

Boom LOWER PPC pressure

Pump 2

delivery

amount

R. Travel PPC pressure

ZX215-1002198

4-176

Structure and Function

Function

Ɣ Use the joystick pilot pressure signal di-

rectly as the hydraulic pump discharge

control signal. Pilot pressure is applied on

the valve stem and, on the other hand, is

collected by the controller. The controller

keeps the discharge amount of the hydrau-

lic pump at the specified value of the cor-

responding pilot pressure according to the

functional relation between the set hydrau-

lic pump discharge amount and pilot pres-

sure. During combined operation, the set

discharge amount of each operation shall

be added.

Operation

Ɣ When the work equipment is operating, the

controller collects the signal of pilot pres-

sure sensor, and determines the control

discharge amount of pump 1 and pump 2

according to the pressure signal.

4-177

Structure and Function

4.9.4.2 Constant power control

Function

Ɣ Calculation of theoretical maximum dis-

charge amount of the pump. The system

applies constant power control. The two

adjustor act together hydraulically, and

Pump P-Q curve

Flow

keep two executing unit of the same speci-

PMax

fication and acting together in synchroni-

zation. The change of pump discharge is

determined by the sum of operating pres-

PMax

sure of the two hydraulic pumps P∑ . When

is met, the sum of the

power of the two hydraulic pumps remains

Pressure

constant below the power of the engine.

ZX215-1002199

Operation

Ɣ When the work equipment is working, the

controller collects the throttle gear signal,,

a constant current value is provided and

pump power control is achieved.

4-178

Structure and Function

ESS control

Function

Ɣ Changing of the engine speed due to load

change controls the pump power, and en-

gine output can be used more efficiently.

(This function can also prevent the engine

from losing control when the machine is

operating under harsh conditions (eg. high

- altitude area).

Operation

The engine control panel controls the target

operating speed of the engine.

Ɣ The engine controller collects the actual

speed signal from the ECM, and preforms

a closed loop control with the target oper-

ating speed. Then, the controller involves

the output of closed-loop control with the

calculation of the solenoid valve control

signal, and sends the final adjusting cur-

rent signal to the pump proportional sole-

noid valve.

Ɣ The solenoid valve feeds pilot pressure oil

to the pump adjustor according to the sig-

nal of the controller, and controls the pump

discharge amount.

4-179

Structure and Function

4.9.5 Valve control function

Swing priortity

Bucket Confluence

Main valve

Press.sensor

Engine

Main

Fuel injectionThrottle

pump

motor

Speed

Servo

sensor

Proportional

valve

Fuel control dial

Monitor

Controller

(CAN bus)

ZX215-1002200

Valve control function

Ɣ Bucket flow control

Ɣ Swing priority control

4-180

Structure and Function

4.9.5.1 Bucket flow control

Function

Swash plate angle

Ɣ Control the pump swash plate angle ac-

cording to the operation of bucket control

lever.

Max

Min

Bucket control lever

PPC pressure

ZX215-1002201

Operation

Bucket confluence

Ɣ When the bucket control lever is operated,

proportional

the controller collects the signal from the

valve current

bucket DUMP pressure sensor and bucket

750mA

CURL pressure sensor, and controls the

bucket confluence proportional valve.

300mA

Bucket control lever

PPC pressure

ZX215-1002202

4-181

Structure and Function

4.9.5.2 Swing priority control

Function

Ɣ Pressurized oil from pump 1 bypasses

bucket 1 valve spool, and flows first to

swing motor valve spool to activate swing

first.

Operation

Ɣ When signals from pump 1 pressure sen-

sor, arm pressure sensor and swing pres-

sure sensor meet the following conditions,

the controller activates the solenoid valve.

The solenoid valve conducts pilot pressure

oil to arm flow controller and limits the al-

ternate circuit of arm 1 valve spool. Swing

valve spool first ensures swing motor

power, preventing the counter acting force

when the arm is retracting from affecting

the positioning of the upper swing struc-

ture.

Operating condition

Ɣ Swing pressure sensor: signal output avail-

able

Ɣ Arm pressure sensor: signal output avail-

able

4-182

Structure and Function

4.9.6 Duo travel speed control

Travel motor

Regulator

Main valve

Travel Speed

solenoid valve

Engine

Injection

Throttle

Main pump

pump

motor

Servo

Fuel control dial

Monitor

Controller

(CAN bus)

ZX215-1002203

4-183

Structure and Function

Function

Ɣ Control travel mode.

Operating condition

Ɣ When Hi speed travel mode on the monitor

is enabled.

Operation

Ɣ When the travel mode is set at LO speed,

the swash plate angle of the travel motor is

the largest, and travel speed is low.

Ɣ When the controller receives the signal

from the travel pressure sensor under the

conditions below, it activates the solenoid

valve. Then, the solenoid valve conducts

pilot pressure oil to the swash plate angle

control valve of the travel motor, and re-

duces the swash plate angle to increase

travel speed.

Remark:

When one side of the tracks is lifted off the

ground by the work equipment and rotating,

pressure at one side of the pump increases,

which makes the lifted track rotate very fast.

When the machine is traveling under Hi speed

mode, even if work equipment is being op-

erated (work equipment pressure sensor is

switched ON), travel mode remains in Hi travel

mode.

4-184

Structure and Function

4.9.7 Engine preheating/overheating alarm

Start switch

Heat

Main valve

Preheat s/w

Preheat relay

Engine

Main

Throttle motor

pump

Coolant

tempe

sensor

Servo

Fuel control dial

Monitor

Controller

(CAN bus)

ZX215-1002204

4-185

Structure and Function

4.9.7.1 Engine preheating

Function

Ɣ Preheating control

Operation

Ɣ This function shall be used in combination

with the preheating switch located on the

right armrest. Turn the engine start key

counterclockwise to the HEAT position and

hold on, the engine will start preheating.

When released, the key will return to the

OFF position automatically and preheating

stops.

Operating condition

Ɣ Power ON. Start key set at the HEAT posi-

tion.

Ɣ Preheating switch: ON

4-186

Structure and Function

4.9.7.2 Engine overheating alarm

Function

Ɣ When engine coolant temperature be-

comes excessively high (above 110°C)

during operation, overheating alarm will be

displayed on the monitor screen.

Operation

Ɣ The controller collects signal from the cool-

ant temperature sensor. When coolant

temperature rises too high, alarming infor-

mation will be generated and transmitted

to the machine monitor.

Operating condition

Ɣ Power ON.

Ɣ Coolant temperature above 110°C.

4.9.8 Engine oil under-pressure alarm

Function

Ɣ The engine controller collects signal from

the engine oil pressure sensor. When en-

gine speed exceeds 600 rpm, if oil pres-

sure is too low, alarming information will be

generated and transmitted to the machine

monitor. The alarm indicator lights up when

the monitor receives the signal.

4-187

Structure and Function

4.9.9 Auto deceleration/acceleration control

Right joystick

Boom

Bucket

Engine

Swing

Left joystick

Arm

Engine

throttle

controller

Fuel control dial

L.Travel

R.Travel

Travel lever

(Throttle signal)

Monitor

Controller

(CAN bus)

Control lever signal

ZX215-1002205

4-188

Structure and Function

Function

Ɣ If all the control levers are neutralized, en-

gine speed will drop to the medium level

automatically to reduce fuel consumption

and noise.

Ɣ If any of the levers is operated, the engine

speed rises to the set level instantly.

Operation

Ɣ About 3 second after all control levers are

neutralized, engine speed will drop to the

Speed (rpm)

first deceleration level about 100 rpm lower

Set rpm

Drop 100rpm

than the set speed. After another 3 sec-

onds engine speed enters low speed (1400

Deceleration

rpm) to reduce the loss of the hydraulic

(1350rpm)

system and engine wear, and reduce fuel

Less than 1 S

less than 2 S

consumption and noise. When the control

Time (s)

lever is operated again, the engine speed

Operated

Unoperated

Operated

rises instantly to the previous level.

Control lever

Ɣ If any control lever is operated while the

ZX215-1002206

engine speed is kept at decelerated level,

engine speed will rise instantly to the level

set by the fuel control dial.

4-189

SANY Crawler Hydraulic Excavator (SY195C9, SY205C9, SY215C9, SY225C9). Shop Manual (2013) - page 14