What are the main performance indicators of internal combustion engines? What does it mean?
Main performance indexes of engine
1.Dynamic index
(1) Effective torque (T+4) (unit: N.m)
The torque output by the engine through the flywheel
(2) Effective power (Pe is expressed in KW)
A. Definition: the output power of the engine through the flywheel is called the effective power of the engine
(3) Engine product nameplate
A. Rated power and rated speed: the power and corresponding speed indicated on the engine product nameplate are called rated power and rated speed
B. Rated power classification: 15-minute power, 1-hour power, 12-hour power, continuous power
Among them, 15-minute power is usually used as the rated power on the vehicle
2.Economic indicators
(1) Expression method: fuel consumption rate
(2) Definition: refers to the mass of fuel consumed by the engine within 1 hour for each 1KW of effective power (g is the unit)
(3) Requirements: the lower the fuel consumption rate, the better the fuel economy.
3.Engine speed characteristics
(1) Definition: the law of engine power, torque and fuel consumption changing with crankshaft speed
(2) Source: engine mapping
(3) External characteristics of the engine: when the throttle is fully open, the speed characteristics obtained from the bench test are called external characteristics of the engine
(4) Part of engine characteristics: the speed characteristics obtained except full throttle opening are called part characteristics
4.Engine working condition and load
(1) Working condition (engine working condition): generally, it can be represented by the power and crankshaft speed of the engine, or it can also be represented 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 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 N/m
Generally speaking, power reflects the absolute speed of the car, or how fast it can run; Torque reflects acceleration, that is, speed up and running energy. Generally speaking, a powerful engine can run very fast, and it can reach speeds of 200 or 300 kilometers. The engine with large torque has good acceleration performance, fast acceleration and flexibility.
