Engine starting
When starting the engine, tighten the parking brake and check whether the gear lever is in neutral position; Power output control, such as water pump, oil pump, sprinkler, etc. , must also be placed in the neutral position.
1-5 Starting sequence and operation method of automobile engine
Sequential operation method
Hot car at room temperature and low temperature
1 1 1 Tighten the parking brake and put the gear lever in the neutral position. Check the quantity of oil and water.
Close the blinds or curtains and preheat the engine with hot water or steam. Make the temperature of cooling water reach 30 ~ 40℃
2 3 Shake the engine with a hand crank for more than 15 revolutions until you feel relaxed. Pull out the choke valve (in winter or when the vehicle is parked for a long time and it is difficult to swing, the spark plug can be removed)
2 3 4 Turn on the ignition switch.
4 5 Press the clutch pedal.
3 5 6 Depress the accelerator pedal moderately.
6 7 Start with crank or starter. The service time of the starter shall not exceed 5 S, and the interval between using it again shall not exceed 15 seconds. Pay attention to safety when using hand crank.
7 8 After the engine is started, warm it up at idle speed. Release the clutch pedal
5 8 9 Push back the choke valve according to the engine heat. When the engine sound is normal and the temperature reaches above 50°C, start in gear.
There are usually three conditions for starting the engine: starting below 5℃ is called normal temperature starting; When it is not lower than 40℃, it is called hot start.
According to the above three situations, the starting sequence and operation methods of gasoline vehicles and diesel vehicles are listed below.
When the cold car starts or the battery is low, the starter should not be used reluctantly, and the crank should be used instead.
Operation and inspection after engine starting.
After the engine is cold-started, it is necessary to maintain a high idle speed and gradually increase the engine temperature, but it is not allowed to slam on the accelerator to avoid serious friction and loss of the engine. When the engine temperature rises to 50 ~ 600C, check the operation of low, medium and high gears, observe that the engine has no abnormal sound, the oil pressure and oil filling amount are normal, there is no burning smell, water leakage and oil leakage, and the barometer pressure meets the requirements, so as to prepare for the shift override.
Third, the engine stopped.
When it is necessary to stop the engine, the driver only needs to turn off the ignition switch and check the deflection of the ammeter pointer to determine whether the circuit has been cut off. Before turning off the engine, you can't slam on the accelerator pedal and leave the car empty. If the engine is running under heavy load or the engine temperature is too high, it should be idling for 1-2 minutes before stopping. When the temperature drops below 900C and the parts are cooled evenly, turn off the switch and stop.
Diesel vehicles should loosen the accelerator pedal and put the fuel handle in the "full off" position. After the engine stops, put it back to the "On" position.
Table 1-6 Starting sequence and operation method of diesel engine
Sequential operation method
Hot car at room temperature and low temperature
1111Tighten the parking brake and put the gear lever in the neutral position. Check the quantity of oil and water.
Close the blinds or curtains and preheat the engine with hot water or steam. Make the temperature of cooling water reach 50℃
2 2 3 Turn on the switch (the charging indicator light is on) and turn the switch to the "glow plug On" position.
3 4 Open the preheating plug for 0.5 ~ 1.5 minutes (2 minutes can preheat to below 5℃), and stop when the preheating indicator light is pink. When the preheating is not enough. It can be preheated continuously for 2-3 times.
4 5 Turn the electrical switch to the "starter on" position. When the starter starts, press the clutch pedal, but don't press the accelerator pedal, and let the engine idle for 3 ~ 5 seconds.
3 5 6 Turn the electrical switch to the "starter on" position and press the clutch pedal at the same time (the thermal generator may not press the clutch). If there is a fuel adjustment device, push it to the "pre-ignition" position. Then, start the engine and press the accelerator pedal to start the starter. The service time of the starter shall not exceed 10 second, and the interval between using it again shall not be less than 20 seconds.
After the engine is started, loosen the clutch pedal and adjust the hand throttle to make the engine run at an idle speed of about 500 rpm. If there is a fuel adjustment device, push it back to its original position. After idling for 3-5 minutes, increase the speed to 1000 ~ 1500 rpm, and start it when the water temperature reaches 60℃ or above.
chapter two
After in-situ driving skills training, students will conduct field driving training on the basis of correctly and flexibly using all operating mechanisms.
Section 1 Preparation and inspection before departure
It is very important to prepare and check before driving. Before you leave the car, you should know the technical condition of the car. Full preparation before driving is a reliable guarantee for the smooth completion of transportation tasks.
The preparation before driving should do the following:
1. Check whether the oil, fuel and cooling water are sufficient. Measure the oil level with a dipstick (after the engine stops running for 5-6 minutes). Check all parts of the car for water leakage, oil leakage and air leakage.
2. Check whether the battery electrolyte meets the specified standards, whether the battery polar line is fastened, whether the high-voltage and low-voltage lines are loose, and whether there is leakage.
3. Check whether the bolts and nuts at the tire, half shaft, transmission shaft and leaf spring are firm. Whether the tire pressure meets the standard.
4. Check the steering device. Whether the connecting parts such as horizontal and straight tie rods are firm and reliable and in good working condition.
5. Check whether the parking and service brakes and clutches are in good working condition.
6. Check the working conditions of lighting, horn and wiper, and check whether the switch is flexible.
7. Check whether the cab door, window, trunk baffle and back door are firm and reliable.
8. Check the on-board tools and accessories, and carry the vulnerable parts necessary for long-distance driving, such as the circuit breaker, distributor head, ignition coil, spark plug, cylinder pad, clutch friction plate, cross shaft, etc.
Cars driving on steep slopes for a long time should also bring triangular wood and snow chains.
Section 2 Starting the Engine, Starting, Driving in a Straight Line and Stopping
Start the engine
Start the engine according to section 8 of Chapter 1.
After the engine is started, the temperature should be appropriate.
begin
When a vehicle starts, it needs a large torque to overcome the static inertia of the vehicle, so it usually starts at a low gear. On the flat and solid road surface, you can use the second gear when starting empty (one gear is needed for a car with four forward gears), and the first gear should be used when loading a car or towing a trailer.
Before getting on the bus, the driver should look around the vehicle, get on and off the bus, and get on the bus in the prescribed order. When starting, keep the correct driving posture. The operation sequence is as follows:
1. Start the engine according to the sequence and method of starting the engine. Observe whether the instrument works normally.
2. Press the clutch pedal and put the transmission control lever into the appropriate gear (first or second gear).
3. Honk the horn according to local regulations, and observe the front, left, right, roof and rearview mirror of the car at the same time to see if there is any situation that hinders the start.
4. Hold the steering wheel with your left hand, hold the parking brake lever with your right hand, and press the button (the steering wheel is on the left).
5. Quickly lift the clutch pedal for direct contact, release the clutch pedal and press the accelerator pedal.
In order to make the vehicle start smoothly, without impulse, vibration and flameout, in addition to the correct use of gear, the cooperation between clutch pedal and accelerator pedal also has a great relationship. When the clutch pedal is depressed, the clutch friction plate is separated from the flywheel surface. In order to shorten the starting time, you can lift the clutch pedal slightly and gradually. When the friction plate is engaged with the flywheel (at this time, the vehicle is slightly shaking and the pedal is jacked up), the pedal must stop slowly, and at the same time, the accelerator pedal should be pressed evenly and slowly, so that the engine speed will gradually increase and the torque will gradually increase, so as to obtain the most sufficient starting power and make the vehicle start smoothly.
Loosening the clutch pedal too quickly or slamming on the accelerator pedal will not only make the vehicle suddenly turn, but also cause the vehicle to impulse forward or stall, and will also damage the engine and transmission parts of the vehicle.
Generally, an empty car starts on a flat and solid road or field, and the second gear can be used; Empty cars should use first gear, trailers should use first gear or rear gear. When starting uphill, you should hold the parking brake lever with one hand, the steering wheel with the other, refuel properly with one foot, and slowly lift the clutch pedal with the other. When the clutch is engaged and the vehicle starts to run, immediately release the parking brake, at the same time completely release the clutch pedal, and properly press the accelerator pedal. Several operations must be closely coordinated to make the vehicle start smoothly. It is not allowed to start uphill without using the parking brake. When starting downhill, slowly release the clutch pedal, slowly press the accelerator pedal and release the parking brake after shifting gears.
When starting on a snowy, icy and muddy road, if the driving wheels slip and idle, measures such as sanding or removing snow mud under the wheels should be taken.
After automatic start-up, the height of louver or radiator curtain should be adjusted to make the engine warm up quickly and keep the temperature at 80-90℃. ..
Drive in a straight line
After the vehicle is started, it enters a straight-line driving state. At this time, it is easy to change the driving posture, which must be corrected at any time and form good habits. When driving, the front wheel is prone to deflection due to uneven road surface, so it is necessary to correct the direction in time. When the front of the car leans to the left (right), turn the steering wheel to the right (left). When the front of the car approaches the driving route, turn the steering wheel back to the right gradually. When correcting the direction, you should play less and return less, so as not to "make the finishing point" in the car. We should carefully understand the swimming clearance of the steering wheel. For example, when the car is driving on the right side of the road, the steering wheel should be on the left side of the swimming gap to prevent the front of the car from leaning to the right.
stop
The general parking method is to use predictive braking, or to slow down and slide into gear, relax the accelerator pedal and press the clutch pedal at the same time: turn the steering wheel to the right appropriately and lightly press the brake pedal to make the car stop smoothly.
After the vehicle stops, the parking brake should be tightened. And put into low gear, stop the engine, and release the clutch pedal and brake pedal. In parking practice, we should pay attention to make the car stop at the predetermined position as far as possible, and gradually meet the requirements of accurate and stable parking.
The third quarter shift change
When the car is driving, due to the change of road terrain conditions and driving speed, the gear shift is quite frequent. Whether or not to shift gears in time, accurately and quickly has a great relationship with maintaining vehicle parts and saving fuel. At the same time, it is also an important symbol to measure the technical status of automobile drivers.
Generally, the first and second gears are low-grade, the third gear is middle-grade, and the fourth and fifth gears are high-grade. The lower the gear, the lower the rotation speed of the drive shaft, but the greater the torque and driving force, so use low gear when starting, going uphill or passing through difficult roads. However, when using low gear, the speed is slow, the engine speed is high, the noise is high, the temperature is high, and the fuel consumption is high, so the low-speed driving time should not be too long. The medium speed gear is used for turning, crossing bridges, general ramps, passing cars or passing through general difficult roads. The driving speed is slightly faster than the low gear, but it is not suitable for long-term driving. Although the high-speed gear transmission is small, it runs fast and saves fuel, and it is used in turn for a long time.
Generally, the ratio of engine speed to shaft speed of transmission shaft is about six to one in the first gear, four to one in the second gear, two to one in the third gear, one to one in the fourth gear and one to one in the fifth gear.
When the car is running, the driver should accurately grasp the shift timing. When changing from low gear to high gear, we must first increase the rotation speed appropriately, and then gradually change from low gear to middle gear and then to high gear, so as to prevent the transmission part from shaking due to lack of power after changing to high gear, and the engine will stall after barely driving.
When the car is driving, it should shift gears according to the changes of road and terrain, and when it feels that the engine power is insufficient, it should gradually reduce the speed. When the original gear is not suitable for driving, you should quickly change from a higher gear to a lower gear. Changing gears too early will consume more fuel, and later the car will stagnate and need to change gears continuously or even start again.
On ordinary roads, when shifting from high-grade to low-grade, it can be carried out through two clutches with empty oil in the middle. However, in muddy roads, muddy roads, steep slopes, soft soil and other areas, the car resistance is large, and the speed will suddenly decrease or even stop when shifting gears. In this case, it is necessary to use two clutches with empty oil in the middle, which will inevitably lead to different peripheral speeds of gears in the transmission, resulting in severe impact. Therefore, under the above circumstances, it is more appropriate to adopt sequential clutch (directly shift the gear lever to a lower gear without inflating after stepping on the clutch pedal). In addition, according to the situation, you can also skip gears (for example, from fifth gear to third gear, or from fourth gear to second gear).