CONTROL PANEL
- The control panel is incorporated into the center panel. To improve the appearance of the interior, the panel is integrated with the audio panel except for models with some audio equipment variations.
- A rear window defogger switch is located in the control panel.
MODELS WITH MANUAL AIR CONDITIONING
- The control panel uses three large-diameter, dial type switches for easy operation and good visual recognition.
Scheme 10
Scheme 11
Scheme 12
MODELS WITH AUTOMATIC AIR CONDITIONING
- A motor driven actuator is used for air outlet switching, driver and passenger side temperature control, and FRESH/RECIRC switching.
- A large sized LCD panel which excels in visibility is used for the control panel.
- To eliminate errors due to heat, the cabin temperature sensor is moved from the control panel to the console side panel.
Scheme 13
Scheme 14
HEATER AND COOLING UNIT
- Having an evaporator core at the front and a heater core at the rear, this single unit combines both heating and cooling functions.
- The heater and cooling unit incorporates mode doors for creating different air flow modes and an air mix door for mixing heated air and outside air.
- On models with automatic air conditioning, the inside of the heater and cooling unit is separated into left and right parts so that the driver and passenger can individually control the temperature.
- In models with an automatic air conditioning, the mode doors and air mixing door are moved by electric-motor-driven actuators.
In models with a manual air conditioning system, the air mix door is moved by a linkage cable.
Scheme 15
BLOWER UNIT
- The blower unit uses a low-noise-type motor.
Scheme 16
FILTER
- Clean air filters are available for all models as dealer option. They can remove dust, cigarette smoke particles and other similar impurities in the air.
Scheme 17
DUCT
- The ventilation duct and defroster duct are located behind the instrument panel. Both the ducts have been modified in the shape to reduce air flow resistance.
- Defrosting air flow is divided at the center, so that air can flow out evenly through a wide center defroster as well as right and left side defrosters.
Scheme 18
COMPRESSOR
As two scrolls (one movable and other fixed) are engaged, a crescent chamber is formed between multiple contact points. The movable scroll cannot rotate on its own axis but orbits instead, so the operating chamber moves inwards while its capacity is reduced. Intake, compression and discharge take place simultaneously at multiple operation chambers, and compressed refrigerant is sent from the discharge hole at the center to the oil separator and then separated in to refrigerant gas and oil before it is output from the discharge port.
Scheme 19
PRESSURE RELIEF VALVE
This valve opens if the pressure of the high-pressure refrigerant gas rises to a dangerously high level to release part of refrigerant into the atmosphere, thus protecting the compressor. The valve is designed to limit the amount of released gas to the necessary minimum.
- Valve opening pressure: above 3.43 MPa (35.0 kgf/cm 2 )
- Valve closing pressure: above 2.75 MPa (28.1 kgf/cm 2 )
- Valve wide open pressure: below 4.14 MPa (42.2 kgf/cm 2 )
Scheme 20
Operating characteristics
Scheme 21
COOLING UNIT
The heater unit and cooling unit are integrated into a single heater and cooling unit.
The cooling section components of this unit include an evaporator, expansion valve, and case.
EVAPORATOR
The evaporator is a laminated type.
When a low-pressure, low-temperature refrigerant is sprayed by the expansion valve into the evaporator, it evaporates and cools the evaporator surfaces.
The cabin air is drawn by the blower and cooled down as it flows over the evaporator. The cooled air then flows passing through the heater unit and delivered into the cabin through vent outlets.
Scheme 22
EXPANSION VALVE
The expansion valve regulates the flow of refrigerant such that heat exchange takes place optimally.
The expansion valve performs two functions; it sprays the high-pressure refrigerant from the condenser using a throttle valve, and it regulates the amount of the spray by changing opening of the throttle valve.
The expansion valve consists of such main components as a heat sensing cylinder, diaphragm, ball valve, spring, and adjusting screw.
Scheme 23
The heat (temperature) sensing cylinder is held in contact with the evaporator outlet pipe so that a pressure corresponding to the sensed temperature may be applied to the chamber above the diaphragm. There is a pressure equalizing hole which communicates with the chamber below the diaphragm to transmit changes in the refrigerant pressure to the chamber. The ball valve is linked with the diaphragm and moves according to changes in the balance between the force applied to the diaphragm and the tension of the spring.
CONDENSER
The condenser is a newly developed subcooling condenser that integrates a multi-flow type condenser and a modulator (gas-liquid separator) into a single unit. The condenser has a high heat-exchange efficiency.
Scheme 24
SUBCOOLING CONDENSER
The new subcooling condenser has a subcooling section where part of the refrigerant that remains in gas form is cooled and reduced into liquid form. This enables almost 100% of the refrigerant to be re-liquefied.
Scheme 25
PRESSURE SWITCH
The pressure switch is a high-pressure side component of the refrigeration cycle (cooling cycle). It consists of a diaphragm that receives refrigerant gas pressure, a snap plate, a rod, contacts that open both when the gas pressure is too low and when it is too high, and a switch that operates at mid-pressure.
The pressure switch plays the following roles
- Prevents "no-gas" operation due to leakage (when gas pressure is too low)
- Protects the system against abnormally high refrigerant pressure (when gas pressure is too high)
- Detects compressor load (mid pressure contact: electric cooling fan output control)
Scheme 26
ON-OFF pressures
Scheme 27
MODELS WITH MANUAL AIR CONDITIONING, CONTROL PANEL, Heater System.>
THERMO AMP (AMPLIFIER)
The thermo AMP detects the temperature at the evaporator outlet to turn off the magnetic clutch circuit when the evaporator temperature drops to a certain level in order to prevent frost from forming on the evaporator.
GENERAL
When the AUTO mode is selected, the automatic air conditioner controls the air temperature and air flow rate automatically.
MODELS WITH AUTOMATIC AIR CONDITIONING, CONTROL PANEL, Heater System.>
IN-VEHICLE SENSOR
The in-vehicle sensor detects the cabin temperature and sends an electric signal corresponding to the temperature to the A/C control module.
This sensor consists of an aspirator and a thermistor, the resistance of which changes in inverse proportion to the temperature. The aspirator operates by a vacuum generated in the heater unit (only when the blower unit is turned on).
Scheme 28
Scheme 29
AMBIENT SENSOR
The ambient sensor uses a thermistor to detect the ambient temperature and outputs a signal corresponding the detected temperature to the auto A/C control module.
The thermistor is covered with a plastic molding to increase its thermal capacity, thus preventing it from being too sensitive to rapid changes in the temperature and enabling the sensor to output an average ambient temperature.
Scheme 30
The ambient sensor is attached to the radiator lower panel at the portion where the radiator panel is located in such a way that it is exposed to outside air most efficiently.
Scheme 31
SUN-LOAD SENSOR
The sun-load sensor uses a photodiode which can convert change in the intensity of solar radiation into change in the electric current. The output signal of the sensor is sent to the auto A/C control module.
Sun-load sensor characteristic
Scheme 32
The sun-load sensor is attached to the front defroster grill.
Scheme 33
EVAPORATOR SENSOR
The evaporator sensor detects the temperature of the air that has passed over the evaporator and transmits a signal corresponding to the temperature to the auto A/C control module.
Scheme 34
Scheme 35
AIR MIX DOOR ACTUATOR
Air mix door actuators are installed at left and right of the heater and cooling unit, and they move the left and right air mix doors independently to the proper position in response to signals from the auto A/C control module. This enables the driver and passenger to control the temperature individually.
Scheme 36
MODE DOOR ACTUATOR
The mode door actuator incorporates an electric motor which turns in one or the other direction in response to signals from the auto A/C control module. The motion of the electric motor is transmitted to each mode door via a linkage and moves the door to the position appropriate for the selected air flow mode.
Scheme 37
FRESH/RECIRC DOOR ACTUATOR
The FRESH/RECIRC door actuator incorporates an electric motor which turns in one or the other direction in response to a signal from the auto A/C control module. The motion of the electric motor is transmitted to the FRESH/RECIRC door via a linkage to move the door to the outside-air introduction or cabin-air-recirculation position.
Scheme 38
FAN CONTROL AMPLIFIER
The fan control amplifier uses a MOS* type field effect transistor. This amplifier steplessly regulates the blower motor voltage (in the range between approximately 3V and 12V) in response to gate voltage signals issued by the auto A/C control module.
Since this fan control amplifier features very small voltage drop, it can handle the maximum voltage for the maximum blower speed without need for a high-voltage relay.
*MOS = metal oxide semiconductor
Scheme 39
MEMO