汽车实用英语-课件7

1、汽车实用英语汽车实用英语Unit 8 Air Conditioning System ServiceUnit 8 Air Conditioning SysteUpon completion of this unit, you should be able to: Overall Objectives Learn key terms about air conditioning system in this unit. Understand the process of inspection and repair of air conditioning system. Use maintenan

2、ce manual to deal with the practical problems.Upon completion of this unit, Task 8.1 Air Conditioning System Overview 空调系统概述Task 8.2 Troubleshooting Air Conditioning System 空调系统故障检测Task 8.3 Pressure detection and Refrigerant replacement 压力检测与制冷剂更换Task 8.4 Detection of sensors 传感器的检测Task 8.5 Compress

3、or and magnetic clutch inspection 压缩机和电磁离合器的检修Tasks Introduction Task 8.1 Air Conditioning Syst When the hot summer comes, it is very bad that automobile air conditioning doesnt work well. It is necessary to look up the repair manual and find a way to troubleshoot the faults of AC. The following tas

4、ks (e.g. pressure detection and refrigerant replacement,detection of sensor, maintenance of air conditioning system, etc.) are the common items in air conditioning system servicing to avoid major damage or keep the air conditioning system running normally.Task Description When the hot summer comes,T

5、ask 8.1 Air Conditioning System OverviewTask 8.1 Air Conditioning SysLearning Preparation air conditioning 空调Airflow 气流Defroster 除雾器Amplifier 放大器blower motor 电风扇Emit 发射Compressor 压缩机Load 负荷Pulley 滑轮solenoid valve 电磁阀 Key terms:Learning Preparation air conStep 1 A maintenance case is provided;Step 2

6、Learn the structure of air conditioning system via a maintenance manual;Step 3 Require students to grasp the key terms in this task;Step 4 Try to describe the structure of air conditioning system;Step 5 Students read relative material;Step 6 Assessment.Plan and Implement Step 1 A maintenance case is

7、 ( ) 1. Refrigerant must be handled in an enclosed area or near an open flame.( ) 2. When handling refrigerant, we neednt wear protection.( ) 3. Dont apply hair spray or stick any foreign matter into the Plasmacluster ion outlet.( ) 4. Do not operate the compressor with no refrigerant.( ) 5. While u

8、sing the battery during inspection, do not bring the positive and negative tester probes too close to each other as a short circuit may occur.Assessment and Feedback True or False ( ) 1. Refrigerant must be ( ) 6. If the check is performed in a dark place, DTC 21 or 24 may be displayed even though t

9、he system is normal.( ) 7. A vacuum pump should be used to perform vacuum purging.( ) 8. Please turn the A/C on before charging with Origerant.( ) 9. Keep the A/C switch on for at least 2 minutes to warm up the compressor.( ) 10. If a gas leak is not detected from the drain hose, remove the blower m

10、otor control from the cooling unit.( ) 6. If the check is perf The purpose of the cars air conditioning system is simple. Its there to keep the car cool during a trip in hot or humid weather. The air conditioner makes the car more comfortable for the driver and passengers alike. Many of todays cars

11、allow the temperature to be set to a certain degree and the air conditioner or heater will adjust the air until the desired temperature is reached. The only drawback to air conditioning is its affect on the gas mileage of the car. Studies are being done to determine how air conditioning affects a ca

12、rs gas mileage as compared to how other things, such as rolling down the windows, affect the gas mileage.8.1.1 How Does Air Conditioning Work? The purpose of the cars The air conditioner works much like the refrigerator used in your home. It has five basic parts: receiver, expansion valve, evaporato

13、r, compressor and condenser. (Fig. 8.1.1) As the compressor raises the pressure of the refrigerant, it also heats it. The hot refrigerant is then pumped into the condenser, where it is cooled off by giving off heat to air passing over the condenser fins. As the refrigerant cools, it condenses into l

14、iquid. Still under high pressure, the refrigerant passes into the receiver. The receiver acts as a storage tank to send refrigerant to the expansion valve at all times. From the receiver, the high-pressure liquid refrigerant passed to the expansion valve. The expansion valve controls the flow of ref

15、rigerant into the evaporator, where a low pressure is maintained by the suction side of the compressor. As it enters the evaporator, the refrigerant begins8.1.2 Air Conditioning System The air conditioner worksto boil by absorbing the heat from the air passing over theevaporator core. Having given u

16、p its heat to boil the refrigerant, the air is cooled and passes into the passenger compartment. The refrigerant continues to boil in the evaporator until all the liquid has been vaporized. From the evaporator, the refrigerant flows back to the compressor to repeat the cycle.Fig. 8.1.1 Air Condition

17、er1- blower; 2- evaporator; 3-expansion valve; 4-compressor; 5-condenser; 6-fan; 7-drierto boil by absorbing the heat Practice Maintenance Manual Reading Air Conditioning SystemPractice Maintenance Manual Practice Maintenance Manual Reading 1. Mode Position and Damper Operation (for Automatic A/C)Pr

18、actice Maintenance Manual Practice Maintenance Manual Reading Functions of Main Dampers:Practice Maintenance Manual Practice Maintenance Manual Reading 2. Air Outlets and Airflow Volume(a) Air Outlets and Airflow VolumePractice Maintenance Manual Practice Maintenance Manual Reading Practice Maintena

19、nce Manual Practice Maintenance Manual Reading The size of the circle indicates the proportion of airflow volume.1: Greater airflow volume at the upper area2: Greater airflow volume at the lower area3: Greater airflow volume at the front4: Greater airflow volume at the rear5: Greater airflow volume

20、at the defroster6: Only for models with automatic air conditioning.3. 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 i

21、s controlled by the A/C amplifier and operates in conjunction with the blower motor.Practice Maintenance Manual Practice Maintenance Manual Reading NOTICE: The Plasmacluster ion generator uses a high voltage, which is hazardous. Therefore, if the Plasmacluster ion generator requires repairs, be sure

22、 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 driv

23、er seat side. When 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 Plasmaclu

24、ster Ions are being generated.Practice Maintenance Manual Practice Maintenance Manual Reading HINT PlasmaclusterTM, plasmacluster, and plasmacluster ions are trademarks of the SHARP Corporation. (b) Operation: (1) The Plasmacluster ion generator produces positive and negative ions from the water mol

25、ecules (H2O) and oxygen molecules (O2) in the air, and emits them into the air. Theseions reduce airborne germs. 4. Blower Motor The blower motor has a built-in blower controller, and is controlled with duty control from the A/C amplifier. 5. A/C Compressor (a) GeneralPractice Maintenance Manual Pra

26、ctice Maintenance Manual Reading (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,

27、 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 2AZ-FE.(5) A solenoid valve that a

28、djusts the suction pressure so that the compressor capacity can be controlled as desired is provided.Practice Maintenance Manual Practice Maintenance Manual Reading (6) The internal valve is provided on models with 2AZ-FE to improve the A/C compressor durability under the high speed and large therma

29、l 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 va

30、lve 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 isapplied to the right side of the pi

31、ston becomes greater than thePractice Maintenance Manual Practice Maintenance Manual Reading 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 sole

32、noid 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 becomesthe 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

33、 plate. As a result, there is no piston stroke and the discharge capacity is reduced. (c) Internal Valve Operation (for 2AZ-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 resul

34、t,Practice Maintenance Manual Practice Maintenance Manual Reading the A/C compressor capacity is reduced, increasing the durability of the A/C compressor. (d) DL type A/C Pulley (for 2AZ-FE) (1) This pulley contains a damper to absorb the torque fluctuations of the engine and a limiter mechanism to

35、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.Practice Maintenance Manual Practice Maintenance Manual Reading 6. Refrigerant line compo

36、nents (for TMC made 2AZ-FE)Practice Maintenance Manual Task 8.2 Troubleshooting Air Conditioning SystemTask 8.2 Troubleshooting Air CLearning Preparation Troubleshoot 故障检测intelligent tester 智能测试仪、诊断仪Recharge 充值CAN communication CAN通信symptom 症状Evaporator 蒸发器ambient temperature 环境温度DTC 故障码Key terms:Le

37、arning Preparation TroubleStep 1 A maintenance case is provided;Step 2 Learn the process of air conditioning system service via a maintenance manual;Step 3 Require students to grasp the key terms in this task;Step 4 Try to describe the process of air conditioning system service;Step 5 Students read

38、relative material;Step 6 AssessmentPlan and Implement Step 1 A maintenance case is ( ) 1. After the vehicle is brought to workshop, the first thing to do is inspecting battery voltage.( ) 2. Replace the battery if the voltage is below 11V.( ) 3. If CAN DTC is output, maybe the CAN Communication Syst

39、em is in trouble.( ) 4. It is enough to check for DTC only once.( ) 5. All of the customers requirements should be customized.Assessment and Feedback True or False ( ) 1. After the vehicle is( ) 6. When troubleshooting a function, dont consider where the function is set.( ) 7. When you check for DTC

40、, you should start the engine and warm it up.( ) 8. DTC is usually obtained by the aid of an intelligent tester.( ) 9. If the DTC 00 is displayed, that means the sensor should be replaced.( ) 10. Push the “OFF” switch to enter the actuator check mode.( ) 6. When troubleshooting8.2.1 How to Repair Ai

41、r Conditioning in a Car An auto air conditioner is essentially a big refrigerator in which many things can go wrong. There are five main elements of the auto air conditioner that can malfunction: thecompressor, condenser, receiver-dryer, expansion valve and evaporator. By familiarizing yourself with

42、 these five parts, you can have an easy time diagnosing anything that goes wrong. Instructions 1. Be familiar with all the major components of your air conditioning system. This includes the compressor, the refrigerant, the condenser, the expansion valve, the evaporatorand the receiver-dryer. 2. Che

43、ck to see if any of your refrigerant is leaking out. While leaks are easy to find, they can be difficult to repair. To check for leaks, simply purchase a fluorescent dye from an8.2.1 How to Repair Air Conditauto-supply store and add it to the system following the instructions on the can. 3. Check to

44、 see if the compressor is turning. Look under the hood while the car is running.The compressor will be the large pump like objects that has rubber and steel hoses attached to it.Make sure the compressors clutch is working when you turn on the air conditioning. 4. Check for anything that needs to be

45、replaced. This can include bad switches, bad fuses, broken wires, a broken fan belt or seal failure in the compressor. 5. Remove as much contaminated compressor oil as you can. To do this, you will have to flush the air conditioning system to get rid of the old oil. Then place new compressor oil and

46、 restart the car to see if the air conditioning starts to work. 6. Use approved flushing agents to clear out the condenser sinceauto-supply store and add it tthese will evaporate quickly and wont leave a residue inside the system. Depending on the extent of the damage you may also need to replace th

47、e entire condenser. 7. Whenever you are cleaning or replacing the compressor it is also a good idea to replace the accumulators or receiver driers. You should consider the accumulator or receiver dryer to be about the same as an oil filter. These can build up with debris that canaffect the performan

48、ce of your air-conditioning system. 8. The expansion valve should be replaced regularly, since even small amounts of debris can affect the natural flow of the refrigerant. There is no repair for restricted expansion valves. However, you can try and test them with a replacement compressor before repl

49、acing them to ensure this is the problem.these will evaporate quickly aPractice Maintenance Manual Reading How to Proceed with TroubleshootingHINT:Use the following procedures to troubleshoot the air conditioning system.*:Use the intelligent tester.HINT：Refer to the DTC CHECK/CLEAR.(b) Delete the DT

50、CS(c) Recheck for DTCs. Based on the DTCs output above, try to force output of the A/C system DTC by simulating the operation indicated by the DTC.Practice Maintenance Manual Practice Maintenance Manual Reading Customize ParametersHINT:The following items can be customized.NOTICE:When the customer r

51、equests a change in a function, first make sure that the functioncan be customized.Be sure to make a note of the current settings before customizing.When troubleshooting a function, first make sure that the function is set to the default setting.Practice Maintenance Manual Practice Maintenance Manua

52、l Reading Practice Maintenance Manual Practice Maintenance Manual Reading DTC Check / ClearHINT*: For AUTO A/C1. DTC CHECK (SENSOR CHECK)*(a) Start the engine and warm it up.(b) Perform the indicator check.HINT: After the indicator check is completed, the system enters the DTC check modeautomaticall

53、y.(c) Read the code displayed on the panel. (Trouble codes are output on the temperature display.)Practice Maintenance Manual Practice Maintenance Manual Reading NOTICE: In the sensor check mode, which is automatically transferred from the indicator check mode, troubleshooting may be partially perfo

54、rmed. Be sure to perform the actuator check, and then the sensor check again. IF the check is performed in a dark place, DTC 21 or 24 may be displayed even though the system is normal.HINT: Refer to the DTC chart (Diagnostic Trouble Code chart) for details of the codes. When there are no problems, D

55、TC 00 is output. As an example, the illustration shows that display code 21 is output. (d) If the steps are difficult to read because they change automatically, push the “MODE” switch to display the steps one at a time so that they can be read easily. The items are displayed step by step each time t

56、he “MODE” switch is pushed. Push the “OFF” switch to finish panel diagnosis. Push the “R/F” switch to enter the actuator check mode.Practice Maintenance Manual Practice Maintenance Manual Reading 2. CLEARING DTC*(a) During the sensor check, press the “FRONT DEF” switch and “REAR DEF” switch at the s

57、ame time.3. DTC CHECK USING INTELLIGENT TESTER(a) Connect the intelligent tester to the DLC3.(b) Turn the ignition switch on (IG).(c) Turn the tester ON.(d) Enter the following menu items: DIAGNOSIS/OBD/MOBD/DTC INFO/CURRENT CODES.HINT:Refer to the intelligent tester operators manual for further det

58、ails.(e) Check the details of the DTCs.(f) Clear the DTCs.Practice Maintenance Manual Practice Maintenance Manual Reading HINT:After repairing the malfunctions, clear the DTC.(1) Connect the intelligent tester to the DLC3.(2) Turn the ignition switch on (IG).(3) Enter the following menu items: DIAGN

59、OSIS/OBD/MOBD/DTC INFO/CLEAR CODES.HINT:Refer to the intelligent tester operators manual for further details.(4) Press the YES button.Practice Maintenance Manual Task 8.3 Pressure Detection and Refrigerant ReplacementTask 8.3 Pressure Detection aLearning Preparation Refrigerant 制冷剂Moisture 水份insuffi

60、cient cooling 冷却不足Circulate 循环Overcharge 过量Condenser 冷凝器expansion valve 膨胀阀Discharge 流量Key terms:Learning Preparation RefrigeStep 1 A maintenance case is provided;Step 2 Learn the process of pressure detection and refrigerant replacement via a maintenance manual;Step 3 Require students to grasp the