System Description
AIR CONDITIONING: AIR CONDITIONING SYSTEM: SYSTEM DESCRIPTION
1. GENERAL
The air conditioning system has the following controls:
2. NEURAL NETWORK CONTROL
* In previous automatic air conditioning systems, the A/C amplifier determined the required outlet air temperature and blower air volume in accordance with the calculation formula that has been obtained based on information received from the sensors.
* However, because the senses of a person are rather complex, a given temperature is sensed differently, depending on the environment in which the person is situated. For example, a given amount of solar radiation can feel comfortably warm in a cold climate, or extremely uncomfortable in a hot climate. Therefore, as a technique for effecting a higher level of control, a neural network has been adopted in the automatic air conditioning system. With this technique, the data that has been collected under varying environmental conditions is stored in the A/C amplifier. The A/C amplifier can then effect control to provide enhanced air conditioning comfort.
* The neural network control consists of neurons in the input layer, intermediate layer, and output layer. The input layer neurons process the input data of the outside temperature, the amount of sunlight, and the room temperature based on the outputs of the switches and sensors, and output them to the intermediate layer neurons. Based on this data, the intermediate layer neurons adjust the strength of the links among the neurons. The sum of these is then calculated by the output layer neurons in the form of the required outlet temperature, solar correction, target airflow volume, and outlet mode control volume. Accordingly, the A/C amplifier controls the servo motors and blower motor in accordance with the control volumes that have been calculated by the neural network control.
3. MODE POSITION AND DAMPER OPERATION
(a) Mode Position and Damper Operation (for Manual A/C)
Functions of Main Dampers:
Functions of Main Dampers::
(b) Mode Position and Damper Operation (for Automatic A/C)
Functions of Main Dampers:
Functions of Main Dampers::
4. AIR OUTLETS AND AIRFLOW VOLUME
(a) Air Outlets and Airflow Volume
(a) The size of the circle o indicates the proportion of airflow volume.
*1: Greater airflow volume at the upper area
*2: Greater airflow volume at the lower area
*3: Greater airflow volume at the front
*4: Greater airflow volume at the rear
*5: Greater airflow volume at the defroster
*6: Only for models with automatic air conditioning.
5. PLASMACLUSTER ION GENERATOR CONTROL
(a) General:
(1) A Plasmacluster ion generator is provided inside the air duct of the side register on the driver seat side to improve the air quality and comfort in the cabin.
(2) This generator is controlled by the A/C amplifier and operates in conjunction with the blower motor.
NOTICE:
* The Plasmacluster ion generator uses a high voltage, which is hazardous. Therefore, if the Plasmacluster ion generator requires repairs, be sure to have them done at a TOYOTA dealer.
* Do not apply any type of spray (such as a cleaning solvent or hair spray) or stick any foreign matter into the Plasmacluster ion outlet, as this could cause improper operation or a malfunction.
* After use, dust may accumulate around the side register on the driver seat side. If this occurs, press the OFF switch on the heater control panel to stop the blower motor before cleaning the area.
* It is normal for the Plasmacluster ion generator to emit a slight sound during operation. This sound is created when electrons collide with the electrode while Plasmacluster ions are being generated.
HINT
PlasmaclusterTM, plasmacluster, and plasmacluster ions are a trademark of the SHARP Corporation.
(b) Operation:
(1) The Plasmacluster ion generator produces positive and negative ions from the water molecules (H2O) and oxygen molecules (O2) in the air, and emits them into the air. These ions reduce airborne germs.
6. BLOWER MOTOR
The blower motor has a built-in blower controller, and is controlled with duty control from the A/C amplifier.
7. BUS CONNECTOR
(a) A BUS connector is used in the wire harness connection that connects the servo motor from the A/C amplifier.
(b) The BUS connector has a built-in communication/driver IC which communicates with each servo motor connector, actuates the servo motor, and has a position detection function. This enables bus communication for the servo motor wire harness, for a more lightweight construction and a reduced number of wires.
8. SERVO MOTOR
(a) The pulse pattern type servo motor consists of a printed circuit board and servo motor. The printed circuit board has three contact points, and transmits to the A/C amplifier two ON-OFF signals for the difference of the pulse phase. The BUS connector detects the damper position and movement direction with this signal.
9. A/C COMPRESSOR
(a) General
(1) The A/C compressor is a continuously variable capacity type in which its capacity can be varied in accordance with the cooling load of the air conditioning.
(2) This compressor consists of the A/C pulley, shaft, lug plate, swash plate, piston, shoe, crank chamber, cylinder, and solenoid valve.
(3) The A/C pulley with built-in magnetic clutch and the lock sensor that detects whether the magnetic clutch is locked are installed on models with the 2GR-FE.
(4) The DL (Damper Limiter) type A/C pulley is installed on models with the 2AR-FE.
(5) A solenoid valve that adjusts the suction pressure so that the compressor capacity can be controlled as desired is provided.
(6) The internal valve is provided on models with 2AR-FE to improve the A/C compressor durability under the high speed and large thermal load conditions. The internal valve is integrated into the solenoid valve.
(b) Solenoid Valve Operation
(1) The crank chamber is connected to the discharge passage. A solenoid valve is provided between the discharge passage (LO pressure) and the discharge passage (HI pressure).
(2) The solenoid valve operates under duty cycle control in accordance with the signals from A/C amplifier.
(3) When the solenoid valve closes (solenoid coil is energized), a difference in pressure is created and the pressure in the crank chamber decreases. Then, the pressure that is applied to the right side of the piston becomes greater than the pressure that is applied to the left side of the piston. This compresses the spring and tilts the swash plate. As a result, the piston stroke increases and the discharge capacity increases.
(4) When the solenoid valve opens (solenoid coil is not energized), the difference in pressure disappears. Then, the pressure that is applied to the left side of the piston becomes the same as the pressure that is applied to the right side of the piston. Thus, the spring elongates and eliminates the tilt of the swash plate. As a result, there is no piston stroke and the discharge capacity is reduced.
(c) Internal Valve Operation (for 2AR-FE)
(1) The internal valve operates when the A/C compressor speed has increased rapidly, the A/C compressor speed is high, or when thermal load has suddenly changed. As a result, the A/C compressor capacity is reduced, increasing the durability of the A/C compressor.
(d) DL type A/C Pulley (for 2AR-FE)
(1) This pulley contains a damper to absorb the torque fluctuations of the engine and a limiter mechanism to protect the drive belt in case the compressor locks. In the event that the compressor locks, the limiter mechanism causes the spoke portion of the pulley to break, thus separating the pulley from the compressor.
10. LOCK SENSOR (for 2GR-FE)
The lock sensor sends A/C pulley speed signals to the A/C amplifier. The A/C amplifier determines whether the magnetic clutch is locked or not by using those signals and engine speed signals.
11. ROOM TEMPERATURE SENSOR (for AUTO A/C)
The room temperature sensor detects the cabin temperature based on changes in the resistance of its built-in thermistor and sends a signal to the A/C amplifier.
12. AMBIENT TEMPERATURE SENSOR
The ambient temperature sensor detects the outside temperature based on changes in the resistance of its built-in thermistor and sends a signal to the A/C amplifier.
13. SOLAR SENSOR (for AUTO A/C)
(a) The solar sensor consists of a photo diode, two amplifier circuits for the solar sensor, and frequency converter circuit for the light control sensor.
(b) A solar sensor detects (in the form of changes in the current that flows through the built-in photo diode) the changes in the amount of sunlight from the LH and RH sides (2 directions) and outputs these sunlight strength signals to the A/C amplifier.
14. EVAPORATOR TEMPERATURE SENSOR
The evaporator temperature sensor detects the temperature of the cool air immediately past the evaporator in the form of resistance changes, and outputs it to the A/C amplifier.
15. A/C PRESSURE SENSOR
The A/C pressure sensor detects the refrigerant pressure and outputs it to the A/C amplifier in the form of voltage changes.