System Description [08/2013 - ]
- GENERAL
- The air conditioning system has the following controls.
Control Outline Manual Control Damper positions and blower speed operate automatically according to the operation of switches such as the temperature control switch, blower switch, mode control switch and inlet control switch. Compressor Control Through the calculation of the target evaporator temperature based on various sensor signals, the air conditioning amplifier optimally controls discharge capacity by regulating the opening extent of the compressor solenoid valve. PTC Heater Control*1 When the engine is running, and the blower motor with fan sub-assembly is turned on, the air conditioning amplifier assembly turns on the quick heater assembly if the conditions listed below are met. - Engine coolant temperature is below specified temperature.
- Outside temperature is below specified temperature.
- Tentative air mix damper opening angle is above the specified value (MAX HOT).
Diagnosis A Diagnostic Trouble Code (DTC) is stored in memory when the air conditioning amplifier assembly detects a problem with the air conditioning system. - *1: w/ PTC Heater
- The air conditioning system has the following controls.
- MODE POSITION AND DAMPER OPERATION
- Mode Position and Damper Operation.
*a Air also blows out of the side registers *b Air also blows out of the side registers and defrosters FUNCTIONS OF MAIN DAMPERSControl Damper Operation Position Damper Position Operation Air Inlet Control Damper FRESH A Allows fresh air to enter. RECIRCULATION B Causes internal air to recirculate. Air Mix Control Damper MAX COLD to MAX HOT Temperature Setting C - D Varies the mixture ratio of warm air and cool air in order to regulate the temperature continuously between hot and cold. Air Outlet Control Damper DEF E, I Air blows out of the center defroster, side defrosters and side registers. FOOT / DEF E, H Air blows out of the front footwell register ducts, side registers and center defroster. FOOT E, G Air blows out of the side registers, front footwell register ducts. In addition, air blows out slightly from the center defroster and side defrosters. BI-LEVEL F, H Air blows out of the front footwell register ducts, front center registers and side registers. FACE F, I Air blows out of the front center registers and side registers.
- Mode Position and Damper Operation.
- AIR OUTLETS AND AIRFLOW VOLUME
- COMPRESSOR (w/ Cooler System)
- General
- The compressoris a continuously variable capacity type with a capacity that varies in accordance with the cooling load of the air conditioning.
- The compressor consists of the shaft, lug plate, piston, shoe, crank chamber, cylinder and solenoid control valve.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
*a Example *b Shoe *c Crank Chamber *d Shaft *e Lug Plate *f Piston *g Cylinder *h Solenoid Control Valve - A variable suction side throttle is used.
- Refrigerant inlet pressure is applied to the top of the variable suction side throttle and crank chamber pressure is applied to the bottom of the variable suction side throttle.
- The pressure difference moves the variable suction side throttle up and down, expanding and contracting the refrigerant inlet passage.
- When the refrigerant flow is at a maximum, the refrigerant inlet pressure is greater than the crank chamber pressure. This causes the variable suction side throttle to move down, fully opening the refrigerant inlet passage and lowering the refrigerant inlet pressure.
- When the amount of refrigerant flow is controlled, the crank chamber pressure is greater than the refrigerant inlet pressure, raising the variable inlet throttle to contract the flow passage.
- These controls suppress noise by reducing pulsation from the refrigerant inlet.
*1 Compressor - - *a Example *b Refrigerant Passage A *c Inlet Chamber *d Variable Suction Side Throttle *e Crank Pressure Inlet Chamber *f High Flow *g Low Flow *h Maximum Volume of Refrigerant *i Controlled Volume of Refrigerant - - Crank Chamber Pressure Refrigerant Flow - A Damper Limiter (DL) type air conditioning pulley is used. A cylinder-type damper is used for this compressor and torque fluctuations have been suppressed, thus making an inertia weight unnecessary. As a result, the weight of the compressor has been reduced.
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
*A Damper Limiter (DL) Type Air Conditioning Pulley *B Conventional Type Air Conditioning Pulley *a Damper *b Inertia Weight
- Operation
- The crank chamber is connected to the suction passage. A solenoid control valve is provided between the suction passage (low pressure) and the discharge passage (high pressure).
- The solenoid control valve operates under duty cycle control in accordance with the signals from the air conditioning amplifier assembly.
*1 Air Conditioning Amplifier Assembly - - *a Suction Passage *b Crank Chamber *c Piston *d Discharge Passage *e Solenoid Control Valve - - - When the solenoid control valve closes (the solenoid coil is energized), a difference in pressure is created and the pressure in the crank chamber decreases. Then, the pressure applied to the right side of the piston becomes greater than the pressure applied to the left side of the piston. This compresses the spring and tilts the lug plate. As a result, the piston stroke increases and the discharge capacity increases.
*1 Air Conditioning Amplifier Assembly - - *a Suction Passage *b Crank Chamber *c Piston *d Discharge Passage *e Solenoid Control Valve *f Crank Chamber Pressure + Spring Force *g Piston Stroke: Large - - - When the solenoid control valve opens (the solenoid coil is not energized), the difference in pressure disappears. Then, the pressure applied to the left side of the piston becomes the same as the pressure applied to the right side of the piston. Thus, the spring elongates and eliminates the tilt of the lug plate. As a result, there is a small piston stroke and the discharge capacity decreases.
*1 Air Conditioning Amplifier Assembly - - *a Suction Passage *b Crank Chamber *c Piston *d Discharge Passage *e Solenoid Control Valve *f Crank Chamber Pressure + Spring Force *g Piston Stroke: Small - -
- General
- QUICK HEATER ASSEMBLY (w/ PTC Heater)
- General
- The quick heater assembly is located above the heater core in the air conditioning radiator assembly.
- The quick heater assembly consists of a PTC element, aluminum fins, and brass plates. When current is applied to the PTC element, it generates heat to warm the air that passes through the unit.
*1 Quick Heater Assembly *2 Brass Plate *3 PTC Element *4 Aluminum Fin
- Quick Heater Assembly Operating Conditions
- The quick heater assembly is turned on and off by the air conditioning amplifier assembly in accordance with the engine coolant temperature, ambient temperature, temperature setting, and electrical load (generator power ratio).
- General
- NO. 1 COOLER THERMISTOR (w/ Cooler System)
The No. 1 cooler thermistor detects the temperature of the cool air immediately after the evaporator in the form of resistance changes, and outputs it to the air conditioning amplifier assembly.
- THERMISTOR ASSEMBLY
The thermistor assembly detects the outside temperature based on changes in the resistance of its built-in thermistor and sends a signal to the combination meter assembly.
- AIR CONDITIONER PRESSURE SENSOR (w/ Cooler System)
The air conditioner pressure sensor detects the refrigerant pressure and outputs it to the air conditioning amplifier assembly in the form of voltage changes.