What are the engine reliability indicators?

The reliability index is an indicator of the engine's ability to continue to work normally under the specified conditions and within the specified time. There are various evaluation methods for reliability, such as mileage on first failure, mean mileage between failures, etc.

。1. Effective torque, the torque output of the engine is called effective torque, that is, the torque of the engine. Generally, the greater the torque of the engine, the stronger its acceleration ability and climbing ability.

Generally, the larger the bore of the engine, the longer the piston stroke, and the greater the torque of the engine. This is also one of the reasons why large displacement engines have more torque.

2. Effective power, the effective work output of the engine per unit time is called effective power, that is, the power of the engine, which is equal to the product of the effective torque and the angular velocity of the crankshaft. Engine power is the most important indicator of engine performance, and the top speed of a car is determined by engine power.

3. Engine speed, the number of revolutions per minute of the engine crankshaft is called engine speed. The speed of the engine is related to the number of work times per unit time or the effective power of the engine, that is, the effective power of the engine changes with the different speeds. Therefore, when indicating the effective power of the engine, its corresponding speed must also be indicated.

4. The average effective pressure, the effective work emitted by the working volume of the unit cylinder is called the average effective pressure, the greater the average effective pressure, the stronger the working force of the engine. Many engines are turbocharged today, and the average effective pressure is higher than that of naturally aspirated engines.

Extended Information: Application of Automotive Engine Performance in Driving:

The commonly used performance indicators of automobile engines are: effective power PE; Effective torque te; Average effective pressure PE and effective fuel consumption rate GE and fuel consumption per hour GT. The relationship between these performance indicators and the operating conditions of the engine is called engine characteristics, including the speed characteristics and load characteristics of the engine.

The relationship between the carburetor throttle opening remains unchanged, and the relationship between the performance indicators of the engine, PE, TE, and GE with the engine speed N is called the speed characteristic of the engine. The speed characteristic of the throttle is called the external characteristic. According to the speed characteristics of the engine, we can conclude that at a lower speed, the torque will increase more and more as the speed gradually increases, and at a certain speed, the torque reaches the maximum value.

Later, as the speed continues to increase, the torque decreases. Similarly, the power of the engine also increases with the increase of speed and torque, and at a certain speed, the power reaches the maximum value, and if the speed increases again, the power decreases. Generally, the working range of a gasoline engine should be between the maximum torque speed and the maximum power speed.

For example, the Jiefang Cai092 type car, the maximum torque speed is 1200 1400 rpm, and the maximum power speed is 3000 rpm.

In the process of driving, when the vehicle needs to overcome large resistance and increase the effective power of the engine, you can not blindly press the accelerator pedal to the end, you should understand the maximum power speed of the vehicle you are driving, and use the accelerator pedal to correctly control the engine speed. Exceeding the maximum power speed will increase the friction loss power of the engine, reduce the mechanical efficiency, increase the fuel consumption, and shorten the engine overhaul cycle.

Power index: characterizes the size of the engine's workmanship ability, economic index: engineThermal efficiencyand fuel consumption rate, environmental performance indicators:

Refers to the quality of engine emissions and noise levels.

Reliability index: the ability to work normally and continuously under specified conditions, and the manufacturability index: the convenience of manufacturing and maintenance.

Compactness index: the degree of compactness of the engine structure, strengthening index: evaluation of the heat load of the engine.

and the capacity of mechanical loads.

The index based on the output work of the crankshaft is called the effective performance index. Mainly: 1) engine dynamics indicators, including effective work and effective power.

Effective torque. Average effective pressure. rpm n and piston average speed; 2) Engine economy indicators, including effective thermal efficiency.

effective fuel consumption rate; 3) Engine enhancement indicators, including liter power plthan the quality of me. Reinforcement coefficient pmecm

The performance index of the engine is used to characterize the performance characteristics of the engine and as the basis for evaluating the performance of various engines. Generally, there are power indicators, economic indicators, strengthening indicators, compact indicators, environmental indicators, reliability indicators, durability indicators, manufacturability indicators, internal combustion engine speed characteristics, etc.

The dynamic index is an index that characterizes the functional force of the engine, and the effective torque, effective power, speed and average effective pressure of the engine are generally used as indicators to evaluate the power of the engine.

The torque output from the engine is called the effective torque, which is the torque of the engine. Generally, the larger the bore of the engine, the longer the piston stroke, the greater the torque of the engine, and the stronger the acceleration ability and climbing ability.

Engine economy indicators include effective thermal efficiency and effective fuel consumption rate. The strengthening index refers to the evaluation index of the engine's ability to withstand thermal load and mechanical load, generally including liter power and strengthening coefficient. The compactness index is used to characterize the overall compactness of the engine, which is usually measured in terms of specific volume and specific mass.

Environmental indicators are used to evaluate engine exhaust quality and noise levels, which are related to human health and the environment on which they live. Each country** has established strict control regulations to reduce the environmental pollution caused by engine exhaust and noise. China implemented the China VI standard in 2020.

The reliability index is an index that characterizes the ability of the engine to work normally and continuously under the specified use conditions. The indicators to evaluate reliability include mileage of the first failure, mileage between failures, and damage rate of major parts.

The durability index refers to the extreme time that the main parts of the engine are worn to the point where they can no longer continue to work properly. It is usually measured in terms of the engine's overhaul mileage, which is the number of miles the car travels between the time the engine leaves the factory and the first overhaul. The vast majority of engines now have an overhaul mileage of more than 200,000 kilometers.

Manufacturability index refers to the index to evaluate the quality of engine manufacturing manufacturability and maintenance process. If the engine structure is well processed, it is easy to manufacture and maintain, which can reduce production costs and maintenance costs.

The engine indication index is used to evaluate the perfection of its internal circulation, reflecting the work of the working fluid in the cylinder on the piston. It is the basis of effective indicators, but it cannot comprehensively reflect the performance of the whole engine; The performance of the engine is based on the work output of the crankshaft, but it cannot accurately indicate the perfection of the internal processes of the engine.

Effective power, effective torque and other dynamic indicators.

There are mainly power indicators, emission indicators and economic indicators. Hope it works for you.

Indication index of the engine: indication work (or cycle indication work): the work done by the working fluid on the piston after the cylinder completes a cycle, expressed by WCI (J).

wci=∮pdv。Average indication pressure pi: the indicated work done per cycle of the working volume of the engine per unit cylinder; Unit:

kpa。Indication power ni: the indicated work done per unit of time, unit:

Indicated fuel consumption rate GI: The amount of fuel consumed per unit of indicated work, expressed by GI, GI (1000 gf Ni) [G kw·h].

Indication thermal efficiency I: the ratio of the actual cycle indication work WCI to the calorific value Q1 of the fuel used, expressed by i, gi — [g kw·h. Valid Indicators:

Mechanical loss power nm: The amount of power consumed due to mechanical loss. Effective power ne:

The power output of the crankshaft to the outside world, unit: [kw]; Effective torque me: is the average torque output of the crankshaft when the engine is working.

Unit:Mean effective pressure pe:

The circulating effective work per unit cylinder working volume. Unit: KPA.

Power per litre nl: The effective power emitted by the engine per litre of working volume. Unit:

kw/l]。Specific weight: the ratio of the net weight g of the engine to the power emitted ne.

ge＝g/ne 。Effective Fuel Consumption Rate: The amount of fuel consumed per unit of effective work.

ge＝1000×gf/ne [g/kw·h]。Effective thermal efficiency: The ratio of the effective power of the engine to the heat Q1 emitted by the fuel consumed.

The main performance indicators of the engine are power chaos indicators (effective torque, effective power and quiet lift rate, etc.) and economic indicators (effective fuel consumption rate), the above indicators are stable and called the reliability of the engine.

The indicators all say that the engine is safe to use, safe and efficient, and can be used clearly within the range of this passing level.

The core index is the indicator that indicates that the engine is in the specified high salary, and in general, it means that it should be specified in the engine.

The performance indicators of the engine mainly include power indicators, economic indicators, environmental indicators, reliability indicators and durability indicators. 2. Dynamic index: It is an index that characterizes the functional force of the engine, and generally uses the effective torque, effective power, and engine speed of the engine as evaluation indicators.

This is the metric that the public pays the most attention to. 3. Engine economy index: generally expressed by effective fuel consumption rate.

4. Environmental indicators: mainly refer to the exhaust quality and noise level of the engine. Emissions and noise levels have become important performance indicators for engines.

The engine dynamics and economy indicators based on the output power of the engine crankshaft are called effective indicators of engine performance. The effective indicators for evaluating dynamics are effective power, effective torque and average effective pressure; The effective fuel consumption rate and the effective efficiency are evaluated for the economy.

1. Effective power, PE dedicated

2. Effective torque, ME indicated

3. The average effective pressure PE is indicated

4 Effective fuel consumption rate GE is indicated

5. Effective efficiency.

Power performance indicators.

1) Effective torque: refers to the torque output by the engine through the crankshaft or flywheel.

2) Effective power: refers to the power output of the engine through the crankshaft or flywheel.

3) Crankshaft speed: refers to the number of revolutions per minute of the engine crankshaft, usually expressed by n, the unit is r min.

2. The economic performance index usually uses the fuel consumption rate to evaluate the economic performance of the internal combustion engine.

3. Environmental performance emission performance indicators include smoke emission, harmful gas (CO, HC, NOX) emissions, noise, etc.

1.Dynamic index The dynamic index is an index that characterizes the functional force of the engine, and the effective torque, effective power, and engine speed of the engine are generally used as evaluation indicators. (1) Effective torque The torque output of the engine is called effective torque, (2) Effective power The effective work output of the engine per unit time is called effective power, (3) Engine speed The number of revolutions per minute of the engine crankshaft is called engine speed, 2

Economy index Engine economy index is generally expressed in terms of effective fuel consumption rate. The amount of fuel consumed by the engine per 1 kW·h of effective work (in g) is called the effective fuel consumption rate.

Reliability is an index to evaluate the comprehensive performance of the technical level of the vehicle. The reliability of a car refers to the ability to complete a specified function under the specified conditions of use and within the specified itinerary. The reliability of the car depends on the inherent reliability of the car itself and the level of maintenance of the car, and is related to the conditions under which the car is used.

As the car lasts longer, the likelihood of failure increases, and the reliability decreases. If maintenance is carried out on the car from the start of operation to the time when it works to t, time t is said to be the maintenance cycle. Before the maintenance interval is reached, the possibility of the car breaking down increases, and after maintenance, the technical performance of the car is restored to a certain extent.

After long-term use and maintenance of the car, its technical performance will decline significantly, and only through repair can the technical performance be greatly improved. It can be seen that automobile maintenance can only maintain the technical condition of the car to a certain extent and improve the reliability of use, but it cannot completely restore its inherent reliability level. Therefore, the car is scrapped after a considerable mileage (i.e., when the limit mileage is reached).

The reliability evaluation index is as follows. (1) Average mileage to first failure. (2) Mean mileage between failures.

3) Equivalent failure rate.

1.Reliability: refers to the ability of a product to complete a specified function under specified conditions and within a specified time.

2.Automobile reliability indicators are commonly used in reliability, failure rate, average life, maintenance, effectiveness, etc. 3Reliability refers to the probability that the product will complete the specified function under the specified conditions and within the specified time4

The failure rate refers to the probability that a product that has not failed at a certain point in time will fail within a unit time after that time.

5.Average lifespan: The most commonly used reliability metric for a product.

For repairable products: The mean time between failures of the product.

Recorded as MTBF

For non-repairable products: The average operating time before product failure (an indicator of the reliability of the vehicle) is recorded as MTTF