CONTROL PANEL
- The HVAC control panel is incorporated into the center panel.
- A rear window defogger switch is located in the control panel.
Scheme 13
Scheme 14
Scheme 15
- The control panel uses three large-diameter, dial type switches for easy operation and good visual recognition. Temperature control dial This dial allows adjusting the temperature of air delivered through the ventilators. Fan speed control dial This dial allows turning on/off the blower and selecting any of the four blower speeds. Air outlet switching dial This dial allows selecting any of the five air flow modes. Rear window defogger switch This switch activates the rear defogger. To prevent prolonged operation when the switch is left on, a timer keeps the defogger activated for 15 minutes after the switch is turned ON (the switch illuminates) and then turns it off automatically. Air conditioning switch (vehicles with A/C) This switch engages (the switch illuminates) and disengages the air conditioning compressor. RECIRC switch When this switch is turned ON (the switch illuminates) the system enters the cabin-air-recirculation mode, and when OFF the system is in the outside-air-introduction mode.
Scheme 16
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Scheme 18
- Servo motors are used for air outlet switching, temperature control, and air intake mode switching.
- The control panel uses three large-diameter, dial type switches for easy operation and good visual recognition. Temperature control dial This dial allows adjusting the temperature of air delivered through the ventilators within a range from 18 to 32°C (65 to 85°F) in 21 steps. Fan speed control dial In manual control, this dial allows selecting any of the four blower fan speeds. Air outlet switching dial In manual control, this dial allows selecting any of the four air flow modes. AUTO switch By operating this switch the system will operate in full automatic mode. The air flow, air outlets switching, air intake mode switching, and the A/C compressor engagement/disengagement are automatically controlled. Air conditioning switch This switch engages (the switch illuminates) and disengages the air conditioning compressor. Defroster switch When this switch is turned ON (the switch illuminates) the system enters defroster mode. When the switch is pressed again the system returns to the mode in which the system was operating before the defroster mode was selected. Rear window defogger switch This switch activates the rear defogger. To prevent prolonged operation when the switch is left on, a timer keeps the defogger activated for 15 minutes after the switch is turned ON (the switch illuminates) and then turns it off automatically. RECIRC switch When this switch is turned ON (the switch illuminates) the system enters the cabin-air-recirculation mode, and when OFF the system is in the outside-air-introduction mode. OFF/BRIGHT switch OFF: all functions are deactivated. (Air intake mode selection remains unchanged.) BRIGHT: When the switch is pressed longer than 1 second, the system enters bright mode and the dimming of the indicators when the position lights and headlights are ON will be cancelled.
Scheme 19
- 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 cooled air.
- In the automatic air conditioning system, actuators switch each mode doors and the air mix door.
- In the manual air conditioning system, air flow mode switching doors and the air mixing door are moved by cables through corresponding linkages.
GENERAL
The air conditioner has a newly-developed subcool condenser for improved heat-exchange efficiency.
As with the previous model's air conditioner, the refrigerant employed is the chlorine-free HFC-134a (R134a), which does not contribute to ozone-layer damage.
A simple system structure is realized by incorporating the receiver dryer with the condenser.
COMPRESSOR
The rotary type compressor consists of an integrally formed rotor and shaft, five vanes, and a cylinder.
As the rotor turns, the vanes that are movally fitted in the rotor slide over the wall of the oval-shaped cylinder while drawing, compressing, and discharging refrigerant gas.
There is a check valve in the rear head to avoid reverse rotation of the compressor which would otherwise occur when the compressor is stopped.
Scheme 20
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: 3.6 MPa (36.5 kgf/cm 2 )
Valve closing pressure: 2.99 MPa (30.5 kgf/cm 2 )
TRIGGER VALVE
This valve applies back pressure to the vanes.
CHECK VALVE
This valve is attached to the refrigerant suction port in the rear head and prevents reverse flow of the refrigerant when the compressor is stopped.
DISCHARGE VALVE
This valve is attached to the outlet port in the cylinder and prevents reverse flow of the refrigerant.
COMPRESSOR OIL
A specified amount of oil is filled in the cylinder and this oil is delivered to various locations by the refrigerant output pressure.
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.
Scheme 21
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 versions 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 used in the air conditioning system is the 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 requefied.
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, and contacts that open both when the gas pressure is too low and when it is too high.
The pressure switch plays the following roles
Scheme 26
- Preventing "no-gas" operation due to leakage (when gas pressure is too low)
- Protecting the cooling system against abnormally high refrigerant pressure (when gas pressure is too high)
- Detection of compressor load (mid pressure contact: electric cooling fan output control)
ON-OFF PRESSURES
