Purpose
The expansion valve atomizes liquid refrigerant to facilitate cooling of the evaporator.
Function
The expansion valve reduces the pressure of liquid refrigerant rapidly to facilitate vaporization of the atomized refrigerant at the evaporator, and adjusts the refrigerant amount sent into the evaporator.
Construction
The expansion valve consists of the following parts:
Diaphragm
Temperature sensor
Shaft
Expansion valve body
Ball valve
Spring
Operation
Adjustment of the refrigerant amount supplied to the evaporator is performed by the ball valve opening angle in the expansion valve.
The opening angle adjustment is performed according to the balance of the following forces:
Refrigerant pressure (Pd) in diaphragm
Refrigerant gas pressure (PI) of evaporator under diaphragm
Spring force (Fs) pushing up ball valve
If the refrigerant gas temperature from the evaporator increases, the expansion valve increases the amount of refrigerant according to the following operations:
The temperature of the temperature sensor tightly sealed against the diaphragm increases.
The refrigerant in the diaphragm warms and the Pd increases.
If this Pd increases more than PI + Fs, the diaphragm is pressed down.
The shaft installed to the temperature sensor end presses down the ball valve.
The amount of refrigerant is increased.
If the refrigerant gas temperature from the evaporator decreases, the expansion valve decreases the amount of refrigerant flow according to the following operation:
The temperature of the temperature sensor tightly sealed against the diaphragm decreases.
The refrigerant temperature in the diaphragm decreases and the Pd decreases.
The Pd decreases less than PI + Fs.
The ball valve installed to the temperature sensor end is pressed up.
The amount of refrigerant is decreased.
Fail-safe
Function not equipped.
Coolant Reserve Tank Removal/Installation
1. Remove in the order indicated in the table.
2. Install in the reverse order of removal.
1
Wiring harness
2
Hose
3
Coolant reserve tank
(See Coolant Reserve Tank Removal Note.)
Coolant Reserve Ta ...
Interior Care
WARNING
Do not spray water in the cabin:
Splashing water on electrical parts such as the audio unit and switches is dangerous
as it could cause a malfunction or a fire.
Dashboard Precautions
Prevent caustic solutions such as perfume and cosmetic oils from contacting the
dashboard. They will ...
Air Bag System [Two Step Deployment Control System]
Outline
The air bag system is a device that supplements the passenger restraint function
of the seat belts. The air bag system will not have the designed effect if the
seat belts are not worn properly.
The air bag system is composed of the following parts:
...