REFRIGERATION SYSTEM
ATC-21
C
D
E
F
G
H
I
K
L
MA
B
AT C
Operation
1. Operation Control Valve
Operation control valve is located in the suction port (low-pressure) side, and opens or closes in response
to changes in refrigerant suction pressure.
Operation of the valve controls the internal pressure of the crankcase.
The angle of the wobble (swash) plate is controlled between the crankcase’s internal pressure and the
piston cylinder pressure.
2. Maximum Cooling
Refrigerant pressure on the low-pressure side increases with an increase in heat loads.
When this occurs, the control valve’s bellows compress to open the low-pressure side valve and close the
high-pressure side valve.
This causes the following pressure changes:
–The crankcase’s internal pressure to equal the pressure on the low-pressure side;
–The cylinder’s internal pressure to be greater than the crankcase’s internal pressure.
Under this condition, the wobble (swash) plate is set to the maximum stroke position.
3. Capacity Control
–Refrigerant pressure on suction side is low during high speed driving or when ambient or interior tempera-
ture is low.
–The bellows expands when refrigerant pressure on the suction pressure side drops below approximately
177 kPa (1.77 bar, 1.8 kg/cm
2 , 26 psi).
Since suction pressure is low, it makes the suction port close and the discharge port open. Thus, crank-
case pressure becomes high as high-pressure enters the crankcase.
–The force acts around the journal pin near the swash (wobble) plate, and is generated by the pressure dif-
ference between before and behind the piston.
The drive lug and journal pin are located where the piston generates the highest pressure. Piston pres-
sure is between suction pressure Ps and discharge pressure Pd, which is near suction pressure Ps. If
crankcase pressure Pc rises due to capacity control, the force around the journal pin makes the wobble
(swash) plate angle decrease and also the piston stroke decrease. In other words, crankcase pressure
RHA473C
SC-36
SERVICE DATA AND SPECIFICATIONS (SDS)
SERVICE DATA AND SPECIFICATIONS (SDS)PFP:00030
BatteryEKS0031Q
StarterEKS0031R
AlternatorEKS0031S
Applied modelQR20, QR25 engine
YD22 engine
Except
for Northern EuropeFor Northern
Europe
Type 55D23L 80D23L 110D26L
Capacity [V - AH] 12-48 12-52 12-64
Applied modelQR20, QR25 engine
YD22 engine
A/T M/T
Ty p eS114-844 M0T87081 M8T71471
HITACHI make MITSUBISHI make
Reduction
System voltage [V] 12
No-loadTerminal voltage [V] 11.0
Current [A] Less than 90 Less than 90 Less than 145
Revolution [rpm] More than 2,700 More than 2,500 More than 3,300
Minimum diameter of commutator [mm (in)] 28.0 (1.102) 28.8 (1.134) 31.4 (1.236)
Minimum length of brush [mm (in)] 10.5 (0.413) 7.0 (0.276) 11.0 (0.433)
Brush spring tension [N (kg, lb)] 16.2 (1.65, 3.64)15.0 - 20.4
(1.5 - 2.1, 3.4 - 4.6)26.7 - 36.1
(2.7 - 3.7, 6.0 - 8.2)
Clearance between bearing metal and armature shaft [mm (in)] Less than 0.2 (0.008) —
Clearance “L” between pinion front edge and pinion
stopper[mm (in)] —0.5 - 2.0
(0.020 - 0.079)—
Movement “L” in height of pinion assembly [mm (in)]0.3 - 2.5
(0.012 - 0.098)—0.5 - 2.0
(0.020 - 0.079)
Applied model QR20, QR25 engine YD22 engine
Ty p eLR1110-713V A3TB0771
HITACHI make MITSUBISHI make
Nominal rating [V - A] 12-110 12-90
Ground polarityNegative
Minimum revolutions under no-load
(When 13.5 V is applied)[rpm] Less than 1,100 Less than 1,300
Hot output current (When 13.5 V is applied) [A/rpm](More than 35/1,300)
More than 70/1,800
More than 91/2,500
More than 110/5,000More than 29/1,300
More than 76/2,500
More than 88/5,000
Regulated output voltage [V] 14.1 - 14.7
Minimum length of brush [mm (in)] More than 6.0 (0.236) More than 5.0 (0.197)
Brush spring pressure [N (g, oz)]1.0 - 3.43
(102 - 350, 3.60 - 12.34)4.8 - 6.0
(490 - 610, 17.28 - 21.51)
Slip ring minimum diameter [mm (in)] More than 26.0 (1.024) More than 22.1 (0.870)
Rotor coil resistance at 20 °C (68 °F) [Ω] 2.16 - 2.46 2.1 - 2.5
