The main performance indicators of the engine are
(1) effective torque (T+4) (unit N.m)
Torque output by engine through flywheel
(2) Effective power (Pe, unit KW)
A definition: the power output by the engine through the flywheel is called the effective power of the engine.
B, calculation formula:
(3) Engine product nameplate
A. Calibration power and calibration speed: The power indicated on the nameplate of the engine product and the corresponding speed are called calibration power and calibration speed.
B. Classification of rated power: 1 5min power,1hr power,12hr power and continuous power.
Among them, the power of 15 minutes is often used as the calibration power in automobiles.
2. Economic indicators
(1) Representation method: Fuel consumption rate (2) Definition: refers to the fuel mass consumed by the engine per 1 kw effective power within1hour (unit: g).
(3) Requirements: The lower the fuel consumption rate, the better the fuel economy.
(4) Calculation formula:
3. Definition of engine speed characteristics (1): the law of engine power, torque and fuel consumption rate changing with crankshaft speed.
(2) Source: engine bench test (3) Engine external characteristics: When the throttle valve is fully open, the speed characteristics obtained through bench test are called engine external characteristics.
(4) Partial characteristics of the engine: The speed characteristics obtained except the full throttle are called partial characteristics.
(5) Engine external characteristic curve diagram
4. Engine working condition and load
(1) working condition (engine working condition): it is generally expressed by the power of the house and crankshaft speed, and can also be expressed by the load and crankshaft speed.
(2) Load: the ratio of the power generated by the engine at a certain speed to the maximum power that may be generated at the same speed (%)
5, engine performance index classification
There are two main indicators of engine performance, one is power and the other is torque.
The unit of power is kilowatt or horsepower, and the unit of torque is nm.
Generally speaking, power reflects the absolute speed of a car, or how fast it can run; Torque reflects acceleration, that is, speed-up performance. Generally speaking, a high-powered engine can run very fast, at a speed of 200 or 300 kilometers. The engine with high torque has good acceleration performance, fast acceleration and flexibility.