According to the relevant national standards, motorcycle model consists of trademark code, specification code, type code, design code and improved serial number, and its composition forms are as follows:

1. Trademark code is represented by the first letter of Chinese phonetic alphabet of each word in the trademark name.

2. the specification code is expressed by the total displacement of the engine, and the displacement unit is ml.

3. The type code consists of the type code and the model code of the motorcycle, and the type code and the model code are respectively represented by the first letter of the capital Chinese Pinyin, which is a representative word in the type name and the model name. (Type code is shown in the following table)

4. Design serial number When the same manufacturer produces vehicles with the same brand, total displacement and type at the same time, but not the same basic model, the design serial number shall be used to show the difference. The design serial number uses Arabic numerals 1, 2, 3 ... to indicate the vehicle design sequence in turn, and it should be omitted when the design serial number is 1. The design serial number shall be separated from the previous type code by the interval symbol "-".

5. The improved serial number is indicated by capital Chinese phonetic letters A, B, C ... in turn.

The model difference between mopeds and motorcycles is that the letter "Q" is added after the specification code, and other regulations are the same as those of motorcycles. Scooter is a new type of vehicle that has appeared in recent years. It was not clearly stipulated in the original standard. In order to facilitate the management of the industry and public security vehicles, it is now stipulated that scooter should add the letter "T" after the specification code in the model.

for example,

XDZ9T

where xdz-Sundiro brand:

9-the displacement is 9ml;

t-scooter.

YH5Q-2D

where YH—— is the code name of Yuhe Machine Factory or Yuhe brand;

5—— the displacement is 5ml;

q-moped;

2-design code, second design;

d-modification code, the fourth modification;

XF125YS-A

among them, xf-happiness brand produced by Shanghai-Yichu Motorcycle Co., Ltd.;

125—— the displacement is 125ml;

ys-two rounds of off-road racing;

A—— improved serial number, and a is the first design;

CJ75BK

CJ-Changjiang brand;

75—— the displacement is 75ml;

b-side three rounds;

k-passenger transport. I ride the curved beam Longxinxiang Feichi LX11-4, where LX is the Longxin brand motorcycle of Chongqing Longxin Motorcycle Co., Ltd., 11 is the displacement of 11ml, and 4 is the design serial number.

Second, the significance of motorcycle engine model

Engine is the heart of motorcycle, and it can be said that engine is the key component to evaluate motorcycle performance. On your motorcycle registration card, the traffic police will fill in the column of engine model. Motorcycle engines are all internal combustion engines, and they are generally gasoline engines!

in order to facilitate the production management and use of internal combustion engines, the national standard (GB 725-82) "Rules for Compilation of Product Names and Models of Internal Combustion Engines" has made unified provisions on the names and models of internal combustion engines.

1. Name and model of internal combustion engine.

The names of internal combustion engines are all named according to the main fuels used, such as gasoline engine, diesel engine and gas engine.

the model of internal combustion engine consists of Arabic numerals and Chinese phonetic alphabet.

The internal combustion engine model consists of the following four parts:

The first part: product series symbol and replacement symbol, which are represented by the corresponding letters selected by the manufacturer according to the needs, but subject to the approval of the competent department.

middle part: it consists of cylinder number symbol, stroke symbol, cylinder arrangement symbol and cylinder diameter symbol (expressed in millimeters, excluding decimal point).

rear: symbols of structural features and use features, which are expressed in letters.

tail: distinguishing symbol. When the same series of products need to be differentiated due to improvement and other reasons, the manufacturer shall select appropriate symbols to represent them.

2. The arrangement order of internal combustion engine models and the meaning represented by symbols

The arrangement order of internal combustion engine models and the meaning represented by symbols are as follows:

3. Examples of model compilation

(1) Gasoline engine

1E65F: single cylinder, two strokes, cylinder diameter 65mm, air-cooled universal type

41Q: four cylinders. Water-cooled vehicle

41Q-4: four cylinders, four strokes, cylinder diameter 1mm, water-cooled vehicle, and the fourth variant product

CA612: six cylinders, four strokes, cylinder diameter 12mm, water-cooled universal type, and CA stands for serial symbol

8V1: eight cylinders, four strokes and cylinder diameter 1. For water-cooled vehicles, TJ stands for serial symbol

CA488: four cylinders, four strokes, with a cylinder diameter of 88mm, water-cooled universal type, and CA stands for serial symbol

(2) diesel engine

195: single cylinder, four strokes, with a cylinder diameter of 65mm, and water-cooled universal type

165F: single cylinder, four strokes, water-cooled universal type. Water-cooled vehicle

6135Q: six cylinders, four strokes, with a cylinder diameter of 135mm; water-cooled vehicle

X415: four cylinders, four strokes, with a cylinder diameter of 15mm, water-cooled universal type, and X stands for serial code

For example, the engine of my motorcycle is LC152FMH, which stands for Longxin.

III. Significance of motorcycle appearance parameters

There are some appearance parameters in the motorcycle manual, such as vehicle length, full width, full height, wheelbase, minimum ground clearance, etc. Generally speaking, if the car body is short and narrow, it has strong maneuverability. The wheelbase is an important parameter. Generally speaking, the larger the wheelbase (motorcycle refers to the front and rear track), the more stable the car will run (the schematic diagram drawn by myself is not used because of its poor effect), but the off-road performance is poor (the power factor is excluded). As you can imagine, the longer the wheelbase, the less the bump height between the driver sitting in the middle of the motorcycle and the ground at the slope ridge; However, under the condition that the minimum ground clearance of motorcycle is the same, the longer the wheelbase is, it is not as good as a car with a small wheelbase when passing through the bump on the ground. The one with a small wheelbase may pass through the bump, but the one with a long wheelbase may run aground.

The overall height of a motorcycle is also an important indicator for evaluating the ride comfort. The higher the height, the higher the center of gravity, and the worse the ride comfort!

In underbone, where I ride, the above indicators are between riding and pedaling!

4. Several indicators reflecting the overall performance of the motorcycle: maximum speed, braking distance and climbing ability

1. Maximum speed: refers to the best driving speed that the car can reach on a well-leveled road surface.

there are strict requirements for measuring the maximum speed of motorcycles. First, the car is required to use the lubricating oil and fuel specified by the manufacturer, carry out the specified running-in, specified kerb quality, specified tires and tire pressure, and preheat; Second, the test driver is required to weigh 7 kg-8 kg, be 17-18 cm tall, wear a single layer of clothes and a manufacturer's helmet, ride in the driving position and sit up straight as required, and dress according to the manufacturer's regulations when the car with a speed of more than 12 km/h is tested. Third, the requirements for the test track, the test has three styles, of which the most basic style is shown in the following figure:

Fourth, the environmental conditions require that the humidity is less than or equal to 9%, the wind speed is generally less than 3 meters per second (gust is 5 meters), and the temperature also has certain requirements (generally above-3 degrees Celsius). )

under the above conditions, the car reaches the maximum speed before entering the test belt, runs on the test belt for 2 seconds, and measures for three times, and the average maximum speed obtained is the designed maximum speed of the car!

for us in underbone, the maximum speed indicated in the general instructions is greater than or equal to 8 km/h, but in our actual riding, some machines are far more than that, and some people at the altar say that the speed is over 11 km/h, which is normal, but we'd better not exceed the specified maximum speed. The reasons are simple: First, from the perspective of safety, don't drive at high speed; Second, exceeding the speed specified by the manufacturer has an impact on the use of the car; Third, the characteristics of underbone determine that the speed cannot be too high. As we all know, among the three types of cars, the curved beam is the lightest. Then, the dynamic load ratio (the ratio of load to body weight) is also the highest, and the driver is also the most difficult to control at high speed.

2. Braking distance: Braking distance is one of the key parameters to measure the braking performance of a car, which means the distance that people have traveled from the start of braking to the complete standstill when the car is at a certain speed. Underbone generally refers to the braking distance of a car at 3KM/h, which is generally less than or equal to 7m.

here we should pay special attention to two points: first, the braking characteristics of curved beams, that is, light weight, narrow tires, small friction with the ground when braking, and correspondingly smaller braking force; Second, the problem of people's reaction time difference. When people's brains make a reaction to brake, it usually takes .6 seconds (s) for this reaction to command their hands and feet to brake. If the vehicle speed is 3km/h, the vehicle has advanced 8.3m (3,/3,6) at this time.

3. Climbing ability: The climbing ability of motorcycle is an important index to evaluate its performance.

the test method of climbing ability in the instruction manual is to select the slope road as shown in the following figure, and the slope road can be hardened with cement.

the motorcycle starts from any point within 1m before the slope with the lowest gear, and measures two times, one is the time within 1m from the test starting point in the figure, which is denoted by T1, and the other is the time within 2m before the slope, which is denoted by T2. When T1 = 1/2 times T2, that is, when t1 is equal to half of T2, the slope angle of the slope at this time is the climbing ability angle of the car. (In actual measurement, because this slope angle is close to the climbing angle of a motorcycle, when the two times of measurement do not meet the requirements, we can measure it by adding or subtracting the mass, and then calculate the angle by using the formula)

Here, we should pay attention to that the climbing ability of 11 underbone is generally greater than or equal to 18 degrees, and that of 125 cars is generally greater than or equal to 2 degrees. Theoretically, this climbing ability is already very ideal. Because, as you can imagine, the angle of stairs in general buildings is less than 3 degrees! At present, the maximum slope of mountain roads that are regularly surveyed and constructed cannot be greater than 15 degrees. The slope we usually see is very steep visually, which is caused by people's visual illusion!

5. Description of parameters reflecting the main performance of the engine: compression ratio, rated power, maximum torque and fuel consumption rate

To understand the above parameters, it is necessary for us to understand the working principle of the engine, as shown in the following two figures:

1. Compression ratio: compression ratio refers to the ratio of the total cylinder volume to the combustion chamber volume, which indicates the degree of gas compression in the cylinder when the piston moves from the bottom dead center to the top dead center.

compression ratio is an important parameter to measure the performance index of car engine. Generally speaking, the greater the compression ratio of the engine, the higher the pressure and temperature of the mixture at the end of the compression stroke, and the faster the combustion speed, so the greater the power of the engine, the better the economy. However, when the compression ratio is too large, not only can the combustion situation not be further improved, but abnormal combustion phenomena such as deflagration and surface ignition will appear, which in turn will affect the performance of the engine. In addition, the improvement of engine compression ratio is also limited by exhaust pollution regulations.

the above-mentioned deflagration means that when the gasoline mixture in the cylinder is compressed to a certain temperature, it will spontaneously ignite and burn, that is, the spark plug will spontaneously burn before sparking. This affects the engine power. If the compression ratio of the engine is higher, the temperature of the compressed mixed steam will be higher, and the requirements for gasoline deflagration resistance will be higher. Compression ratio is an important basis for choosing gasoline for a car. The higher the compression ratio, the higher the grade of gasoline.

generally speaking, the compression ratio in underbone is 9.1:1, and the minimum gasoline grade required is 9!

2. Effective power and rated power

Effective power refers to the actual power that the engine can output on the crankshaft at a certain speed, expressed in KW;

there are generally two kinds of calibration power, one is the actual effective power of the engine at the maximum speed; The second is the maximum effective power that the engine can run continuously for 15 minutes, 1 hour, 12 hours and for a long time. Generally, motorcycles use the former to indicate the rated power. For example, underbone is generally 5KW/8+-5R/min, that is, the output power is 5KW at 8rpm plus or minus 5rpm.

Power is now expressed in kilowatt international units, which is not as intuitive as horsepower in China. We should remember the conversion between kilowatt and horsepower: 1KW =1.36 (metric) horsepower =1.34 (British) horsepower. A underbone with a rated power of 5KW is equivalent to 6.8 horsepower.

3. Maximum torque and effective torque

Effective torque refers to the rotational torque that can be output from the engine flywheel, and the unit is Newton meters (N.M). It refers to the pressure on the piston crown during the power stroke, minus the friction loss of moving parts and the force consumed by driving various auxiliary devices, which can be output by the crankshaft flywheel. The greater the effective torque at a certain speed, the better the engine performance. Newton mentioned here is the unit of force, and one kilogram is equivalent to 9.8 Newton.

the maximum torque is the maximum torque that the engine flywheel can output to the outside when the engine is rotating at a certain speed. For motorcycles, it is not that the greater the engine speed, the greater the torque. Generally, the maximum torque of a bent beam with a displacement of 11 is 6.5N.M/6R/min, that is, when the engine speed is 6 rpm, the maximum torque is 6.5 Newton. The maximum straddle torque of 125 displacement is 1N.M/6R/min. The torque of 495 diesel engine is 21N.M at 16 rpm.

4. Fuel consumption rate

refers to the weight of fuel consumed by the engine per hour. This is an important index to assess the economic performance of each engine or internal combustion engine, including automobiles and motorcycles.

because the power of each engine is different, the fuel consumption can't really indicate the economy of the engine. In order to compare, it is necessary to find out the fuel weight consumed by outputting 1 kW in each hour of the engine. The unit is g/kw.h (g/kw.h).

at present, the fuel consumption rate of internal combustion engines in the world is: diesel engines are generally 21-285g/kw.h, and gasoline engines are generally 285-41g/kw.h. Because motorcycles are generally single-cylinder, their fuel consumption rate is higher than that of multi-cylinder internal combustion engines such as automobiles, generally 35-38g/kw.h! The fuel consumption rate of the engine of Longxin curved beam motorcycle I ride is 367 g/kW h, and the minimum fuel consumption rate of Longxin engine is 354 g/kW h. According to the author's reference, among the motorcycle engines in the world, the best fuel consumption rate is above 35!

VI. Fuel consumption per 1 kilometers of motorcycles