First, the classification of tractors
Tractors may generally be classified in one of the following ways.
(1) Classification by purpose
1. Industrial tractors
Mainly used in road construction, mining, water conservancy, petroleum and construction projects, but also can be used in farmland capital construction operations.
2. Forestry tractors
Mainly used for forest harvesting, that is, to cut down the wood collection and shipped to the forest farm. Special machines and tools can also be used for planting trees, afforestation and logging
operations, such as J-80 and J-50A tractors. It is usually equipped with a winch, a board and an obstacle removal device.
3. Agricultural tractors
Agricultural tractors are mainly used for agricultural production. According to their different uses, they can be divided into:
(1) Ordinary tractors
It is characterized by a wide range of applications, mainly used in general conditions of farmland mobile operations, fixed operations and transport operations, such as the bumper harvest - 180, Taishan
- 25, Iron Ox - 650 and other models of tractors.
(2) Intertillage tractor
Mainly suitable for intertillage operations, but also used for other operations, such as Changchun - 400 is a universal intertillage tractor. It is characterized by the tractor from the ground clearance is
large (generally in 630 mm above), narrower tires.
(3) The gardening tractor is mainly suitable for orchard, vegetable field, tea forest and other places to work. It is characterized by small size, flexibility and small power, such as walking tractor and small
four tractors.
(4) Special type tractors
It is suitable for operation in special working environment or tractor adapted to special needs. Such as boat tractor (such as hubei production of various types of plowboat, rolling boat), mountain tractor
s, paddy tractors, etc.
(2) Classification according to walking devices
1. Crawler (also called chain track) type tractor
The moving device of the crawler tractor is the crawler, which is mainly applicable to the work in the field of soil clay, wet land, farmland water conservancy, earthwork and other farmland capital
construction. At present, China's production are all full-track tractors, such as Dongfanghong - 75, Dongfanghong - 802, Dongfanghong - 70T, Dongfanghong - 1002/1202 and other models of tractors.
2. Wheeled tractor
The walking device of a wheeled tractor is wheels. According to the number of its walking wheels or axles, it can be divided into two types: walking tractor and wheeled tractor:
(1) Walking tractor
Walking tractors can also be divided into the following categories according to different methods of driving farm tools:
(1) Traction type walking tractor can only be used for traction operations, such as traction plough and rake for farm work, traction trailer transportation, etc.
(2) The driven walking tractor is integrated with the rotary tiller, which can only carry out rotary tillage and cannot do traction work.
(3) It combines the operation performance of the two types mentioned above. Due to its wide range of use, so the current production of walking tractors are mostly of this kind.
(2) Wheeled tractor
Its walking wheel shaft has two, such as the wheel shaft has three wheels called three-wheel tractor; If four wheels are called four-wheel tractors. The wheel type tractor that we say commonly is the
tractor that points to two axles 3 wheel and 4 wheel these two kinds of types, our country produces at present and the most extensive application is 4 wheel tractor. According to different driving types,
four-wheel tractors can be divided into:
1) Two-wheel driven wheeled tractor
Generally for the rear two wheel drive, the front two wheel steering. The designation of the drive type is expressed as 4 by 2 (4 and 2 represent the total number of wheels and the number of drive wheels
respectively). In agriculture, it is mainly used in general field operations, irrigation and drainage, agricultural and sideline products processing and transportation.
2) Four-wheel drive wheeled tractor
Both front and rear wheels are driven by the engine. The driving type code is 4 x 4. In agriculture, it is mainly used for heavy clay, deep turning loudly, muddy road transportation and other operations.
Used in forestry for harvesting and short-haul transportation.
This is a tractor for paddy fields created in Our country. Its feature is to support the weight of the whole machine with the hull, suitable for lake field, deep mud foot paddy field work.
4) Tiller machine is a kind of simple agricultural power machinery newly developed in China in recent years, with simple structure and single-wheel or double-wheel drive, which is suitable for small plot
hydrotillage and dry tillage.
(3) Classification by power
1. The power of large tractor is over 73.6 kw (100 HP).
2. Power of medium tractor is 14.7 ~ 73.6 kw (20 ~ 100 HP).
3. The power of small tractor is less than 14.7 kw (20 HP).
Ii. Characteristics of different types of tractors
Different types of tractors have different characteristics. They are characterized not only by their structural formulas, but also by their size, weight, material consumption, manufacturing costs, traction,
and range of adaptation to soil and crops. It is important for us to buy and sell tractors to understand that different tractors have different characteristics.
(1) Crawler tractors
As crawler tractor is supported on the ground by winding crawler, the crawler has a large contact area with the ground and small pressure (pressure per unit area). For example, the grounding pressure
of Dongfanghong -- 802 model is 44.1 kilpa (0.45kg/cm2), so the tractor is not easy to sink. Since there are many shoe thorn on segments in soil, easy to hold soil layer, is not easy to slip on wet or
muddy soft soil, so have good traction adhesion performance, compared with other types of similar power tractor, it can send large with gravity, thus crawler tractor for good adaptability to different
ground and soil conditions, and can do other types of tractors unqualified for forest or the commune and farmland capital construction, such as heavy work. Its disadvantages are large and bulky, heavy
metal consumption, high price and maintenance, less supporting agricultural machinery and tools, narrow operating range, easy to destroy the road and not suitable for road transport. Therefore, the
comprehensive utilization performance is low.
(2) a two-wheel driven wheeled tractor
Its characteristic basically is opposite with crawler tractor. It's smaller, lighter, uses less metal and costs less to maintain. Supporting agricultural machinery and tools more, the scope of operation is wider,
can be used for road transport, the time used each year is longer, so the comprehensive utilization performance is higher, in our country two wheel drive wheeled tractor main production and sales are
relatively large. Its disadvantage is that the ground pressure is strong, working in the field when the tire pressure is generally 83.3 ~ 137.2 kpa (0.85 ~ 1.4 kg/square centimeter), hard road is generally
147 ~ 196 kPA (1.5 ~ 2.0 kg/square centimeter), easy to sag; In wet muddy or soft soil easy to slip, traction adhesion performance is poor, can not give out a large traction. Therefore, the working quality
of the wheeled tractor driven by two wheels is not as good as that of the crawler tractor when it needs great traction or when the road surface and soil conditions are poor (such as opening up, digging
deep, farmland capital construction, climbing over the road surface obstacles, etc.).
(3) four-wheel drive tractor
Its characteristic is between two wheel drive wheel tractor and crawler tractor, it is the type which has both some firewood advantage. Because it is four-wheel drive, its traction performance is 20% ~
50% higher than that of two-wheel drive wheeled tractor. It is suitable for hanging heavy or wide high efficiency farm tools, and also suitable for farmland capital construction work. The working quality
of the tractor is similar to that of the crawler tractor when working on medium temperature soil, but the difference is great when working on high humidity sticky heavy soil. In the structure, it is more
complex than the two - wheel drive wheel tractor, high price. But it consumes less metal than crawler tractors and costs less.
(4) Walking tractor
It is characterized by volume, light weight, simple structure, cheap price, flexibility and good performance through. It is not only a small paddy field, dry field and hilly area of good tillage machinery, and
suitable for orchards, vegetable gardens many operations. In addition, the walking tractor can also be used with a variety of agricultural and sideline products processing machinery supporting, can be
fixed operations and short-distance transport, the use time is very long every year, comprehensive utilization performance is very high. Therefore, among the tractors produced and used in Our country,
the number of walking tractors is the largest. Its disadvantages are small power, low productivity, poor economy and high labor intensity in paddy fields.
(5) Ship-shaped tractors
At present, the main type of boat tractor is machine farming and machine rolling ship. It is a new type of tractor developed recently in paddy fields of south China. It is mainly used in paddy fields and
lake fields as power and plowing, harrowing, rolling machines and tools; If the drive rotation for the rubber wheel can also be used as a power with trailer transport. Its working principle is to make use
of the weight of the whole hull support, and push the hull forward through the action of the iron wheel, which is usually wedge-shaped, with the soil layer, and drive the supporting farm tools to work in
the paddy field. In low-lying land, mud, no hard bottom, cattle and tractors are difficult to work in the field, because it does not sink, does not destroy the soil, forward resistance is small, so it has a
great adaptability than the general type of tractors and oxen, is a popular tractor.
The name and model of the tractor
Names and models of old products of tractors
The name and model of tractor products are generally compiled according to the following principles before the promulgation standard of the Tractor Product Model Establishment Rules (NJ189-79)
has not been issued.
1, the name of the tractor should be able to represent its function and characteristics. It is generally composed of the base name and the additional name. The basic name is tractor, and the additional
name is generally distinguished by the characteristics of the walking part, listed before the basic name, such as crawler tractor, wheeled tractor, walking tractor, etc.
2. The model of the tractor is composed of two parts, namely, the Chinese characters with political significance or place names or indications, and the approximate value of the rated power (horsepower)
by the internal combustion engine, separated by a dash line "--". Such as: Dongfanghong - 802, Tieniu - 55, Dongfeng - 12, Shanghai - 50, the material - 50 and other models.
Comprehensive above, visible tractor old product name and model compilation is very simple. The full name of the tractor is illustrated as follows:
(1) Dongfeng 12 walking tractor. Represents the power of 12 horsepower, model for dongfeng - 12 - type walking tractor.
(2) Tieniu-55 tractor. Represents the power is 55 horsepower, the model is iron ox - 55 type wheel tractor (in the tractor full name general "wheel" is not marked and omitted).
(2) Rules for the compilation of tractor models
On November 7, 1988, the Ministry of Mechanical and Electronic Industry issued the Code for Model Compilation of Tractors for Agriculture and Forestry. The national professional standard code is ZBT6
0004-88, which is introduced as follows:
The standard stipulates the composition and compilation method of agricultural and forestry tractor model, which is applicable to the compilation of agricultural and forestry tractor model.
1. Tractor model is generally composed of series code, power code, type code, function code and distinguishing mark, arranged in the order shown in the picture.
2. The series code shall be represented by no more than two capital Chinese pinyin letters (I and O shall not be used for the last letter) to distinguish different series or models of different designs. If not
necessary, the series code may be omitted.
3. Power code is expressed as a round number near the calibration power value of the engine. Power is measured in kilowatts (kM).
Four, the use performance of tractor
The performance that the tractor shows in use process, call the use performance of tractor, it is the important basis that evaluates tractor. When we operate tractors, we will encounter problems in the
use performance of tractors in various work such as preferential purchase, organizing accessories, commodity inspection, publicity and promotion, sales, "three guarantees" and so on.
(1) The reliability of the tractor
The reliability of tractor, it is to show the reliable degree that tractor works in specified use condition and time. Usually measured by the service life of tractor parts, reliability is an important index to
evaluate tractors, because the lower the reliability, the shorter the service time, the lower the value created, and at the same time increase the supply of spare parts, affecting the production, the user is
not welcome, but also affecting our operation.
Due to the different working conditions and different manufacturing levels of each part of tractor, their life standards are also different. Before the first overhaul, the service life of all parts of general
farm tractors should be as follows: 5000 hours of engine, 6000 hours of transmission system, 3500 ~ 5000 hours of walking system, 750 hours of trouble-free working. The main parts also have corre－
sponding provisions. When we are organizing the supply of tractor accessories, we should understand the situation from the production plant and users, grasp these performance indicators, and expl－
ore the regularity. To ensure product quality, all sorts of tractor (include complete machine and main spare parts) specified to be sure to use period clearly, in former agriculture wants a ministry to iss－
ue "3 pack" detailed rules to stipulate the period of tractor be sure to use must not be less than one year, but use accumulative total does not exceed 1500 working hours, this is former agriculture ma－
chinery ministry to be sure to use the minimum requirement of period.
Economy of the tractor
The economy of tractor is the cost that points to the place that tractor consumes when be being used. Economy of tractor mainly refers to economy of fuel consumption. The skid rate, rolling resistance,
lubricating oil consumption, maintenance and depreciation of the tractor also affect its economy. The economy of tractor fuel consumption is evaluated in terms of fuel consumption per kilowatt-hour,
that is, specific fuel consumption. For tillage, it can be measured in terms of fuel consumption per acre.
The economy of tractors is very important to the agricultural machinery companies of users and distributors. It can be seen on the market that tractors with good economy are popular and generally sell
well.
The traction and adhesion performance of the tractor.
Tractive performance of tractor is the ability of tractor to exert tractive force. Strong traction means strong traction. The adhesion property of the tractor is the ability of its walking mechanism to attach
to the ground (" grasp "the soil layer). Good adhesion, traction performance is also good, so the two are often mentioned in the same breath. The adhesion performance is mainly better than that of tra-
ctor. The adhesion performance of four-wheel drive is better than that of two-wheel drive tractor. The adhesion performance of high-pattern tire is better than that of low-pattern tire.
Adhesion performance is strong, the tractor used for traction power can be fully developed, so the tractor with the same power, adhesion performance strong, its traction. As tractor is mainly used for tr-
action operations, the power of internal combustion engine on the tractor should not only be looked at when evaluating whether the tractor has strength, but also the power and traction force of tractor
should be compared.
The passing performance of the tractor
It includes two aspects of ground pass performance and row pass performance. The passing performance to the ground refers to the passing performance to various surfaces. If the tractor can run smoo-
thly in wet muddy, low-lying water, snow and ice slippery road ground, work normally in wet, soft or sandy soil in the rainy season, pass on narrow crooked road, easy to climb over ridge, etc., it shows th-
at the tractor has good passing performance. Crosswise performance refers to the performance of the tractor passing between crops (or under fruit trees). If the tractor works on the road or under the fru-
it tree, it has better performance if it hurts less branches, leaves and fruit and less pressure and damage root seedlings.
As a general rule, the appearance of tractors, small size, light weight, walking device on the surface ground pressure is small, the tractor low ground gap (gap), through the performance is good, the grou-
nd pressure is mainly associated with the type of machine and walking device, light weight, large walking device grounding area (e.g., caterpillar), earth pressure is small. Intertillage tractor (be like Chang-
chun - 400 model tractor) leave ground clearance is big, can assure when intertillage not easy damage the branch leaf of intertillage crop to wait.
The mobility of the tractor
It includes the linearity and maneuverability of the tractor. When the tractor moves forward or backward in a straight line
It does not automatically deviate from the straight direction, but after deviating due to the influence of the outside world, it has enough ability to automatically return to the positive, which is called good
linearity. The tractor that says normally runs deviation, point to a tractor to move namely linear sex is not good meaning. Tractor manipulative performance is to point to the performance that tractor can
travel and brake according to need route, start reliably. Tractor operation light, flexible, small turning radius, braking, smooth start, reliable gear, known as good control.
(vi) Stability of tractors
It means that the tractor can maintain its own stability, prevent the performance of rolling over, especially when the tractor is driving on the slope, its stability is more important. It is mainly related to the
height of the center of gravity of the tractor and the position of the center of gravity between wheelbase and wheelbase (track for gauge). The tractor's center of gravity is low, wheelbase, wheel base (or
gauge) is large, and the stability is good. Generally speaking, although the tractor from the ground clearance through the performance is good, but the amplitude from the ground clearance is high, so
that its center of gravity also improved, so the stability is poor.
The productivity and specific productivity of tractors
The work done by a tractor in unit time (measured in hours) is called the productivity of the tractor. The work done by the tractor per kilowatt-hour is called the tractor specific product rate. Tractor prod-
uctivity is usually used to measure the working efficiency of tractors with the same power, while tractor specific productivity is used to measure the working efficiency of tractors with different power. The
productivity and specific productivity of the tractor are closely related to the power, traction and adhesion performance of the tractor and the coordination degree when working together with agricultur-
al machinery and tools.
(8) the structural weight of the tractor and the specific weight of its structure
The structure weight of tractor is to point to did not add oil, water, did not assemble weight, did not sit the weight of driver tractor. The use weight of the tractor includes the weight of oil, water, walking
tractor and also includes the weight with farm tools (rotary tiller or plough). The weight of the tractor per kilowatt is called the structural specific weight. The structural specific weight is an important index
to measure the metal consumption and technical level of the tractor.
The afore-mentioned of tractor these use performance and its index some may have contradictory place, when choosing excellent choose and buy and evaluate, should the suit limits of tractor and use co-
ndition and requirement cooperate to rise to consider, just be appropriate. These performance and index of each kind of tractor, have a regulation commonly in product use instruction book or concerne-
d technical document.
