Mazda 3 since 2003
1. Operation and maintenance of the car
2. Engine
3. Transmission
4. Running gear
5. Steering mechanism
6. Brake system
7. Onboard electric equipment
8. Body
8.1. General information
8.2. Hinged components of a body
8.3. Body glazing
8.4. Seats
8.5. Conditioner and heater
8.5.1. Coolant
8.5.2. Air filter
8.5.3. Block of the air conditioning system
8.5.4. Evaporator
8.5.5. Broad valve
8.5.6. Condenser
8.5.7. Check of a radiator of a heater
8.5.8. Removal and installation of a back air duct
8.5.9. Removal and installation of the compressor of the air conditioning system
8.5.10. Dismantling and assembly of the obgonny coupling
8.5.11. Adjustment of the obgonny coupling
8.5.12. Check of the obgonny coupling
8.5.13. Removal and installation of the condenser
8.5.14. Check of the condenser
8.5.15. Removal and installation of lines of coolant (LF)
8.6. Tables


8.5.5. Broad valve

The broad valve provides sharp reduction of pressure of liquid coolant.
At the same time coolant is sprayed that facilitates evaporation process.
The broad valve also regulates a consumption of the coolant given to the evaporator.
The consumption of coolant is regulated by the size of opening of the spherical valve in the broad valve.
The size of opening is regulated by balance of pressure R-134a upon a diaphragm and the resulting pressure force at the exit of the evaporator (PI) – on the lower part of a diaphragm and force of a spring (Fs) operating on the sharovy valve.
When PI increases, temperature of the temperature sensor about a diaphragm increases, and Pd heated R-134a – increases by a diaphragm.
When Pd is more than PI + than Fs, the diaphragm caves in down, and the shaft attached to the end of a core of the temperature sensor pushes the sharovy valve down, increasing a coolant consumption.

Принцип действия расширительного клапана
Fig. 8.65. Principle of operation of the broad valve: 1 – diaphragm; 2 – temperature sensor; 3 – shaft; 4 – sharovy valve; 5 – spring; 6 – from the evaporator; 7 – to the evaporator; 8 – from the condenser; 9 – on the condenser; 10 – spring force; 11 – HFC-134a pressure; 12 – pressure at the exit

When coolant temperature at the exit of the evaporator decreases, PI + Fs becomes more, than Pd, the sharovy valve rises, and the consumption of coolant decreases.

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8.5.4. Evaporator
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8.5.6. Condenser