The parameters of the operator's workplace should be set on the basis of the anthropometric data of the operators, i.e. the base measurement point should be closely connected with the operator. In the automotive industry, the hip point is taken as the base point, located at the intersection of the vertical plane passing through the longitudinal plane of symmetry of the seat, with the theoretical axis of rotation of the hip relative to the human torso. The human torso is imitated by a mannequin. Given the complexity of manufacturing the dummy itself, as well as certain difficulties for testers in installing it, especially on powerful tractors with a single cab (the need to lift the dummy to a great height), the tractor industry simplified the device for determining the base point. As the base (or reference point of the TOC seat), a point in the longitudinal plane of symmetry of the seat is taken, in which plane 7 intersects, tangent to the rear surface of the lower back of the device for determining TOC (Fig. 1.1), and the horizontal plane // intersecting the lower surface the base of the device at a distance of 150 mm in front of plane I. To determine the TOC, this device is installed so that its longitudinal plane of symmetry coincides with the longitudinal plane of symmetry of the seat. The appliance is then loaded with a vertical force of 550 N at a point 50 mm in front of point A, with both parts of the backrest of the appliance pressed lightly against the seatback. If it is not possible to ensure that the device is firmly in contact with the lower part of the seat back, then only the lower part of the backrest is placed vertically and lightly pressed against the seat back. If it is not possible to ensure a stable contact of the device in the upper part of the seatback, then both parts of its backrest are placed vertically and lightly pressed against the seatback. The reference point of the seat is also related to the operator to a certain extent - it lies in the plane of symmetry of the operator on the line of intersection of the planes tangent to the back and to the hip joints. The inconvenience of using TOS is due to the fact that when directly measuring it on a tractor, the position of the device loaded with a force of 550 N is determined relative to some basic element (for example, the cabin floor), and then the dimensions are transferred to the drawing. It is also possible to install vertical posts on both sides of the seat, interconnected by a jumper or cable in the area where

line of intersection of planes tangent to the cushion and back of the device.

To determine the size and design of the workplace for the operator of earthmoving machines, the reference point of the seat (CTS) is taken as the base one, in which the vertical plane passing through the center line of the seat and the theoretical axis of rotation of the thigh relative to the human torso intersect. An experimental test carried out in various countries showed that the deviation of the CTC from the intersection point of the torso - thigh does not exceed ± 10 mm. CTS, like TOC, can be defined on the seat itself, set in the workspace on the machine, or installed directly by the seat manufacturer. To determine the CTS, the device shown in Figure 1.2 is used. To determine the position of the reference point (CTS), the seat is set to the middle position of its adjustments horizontally, vertically, angularly and by the weight of the operator (in the latter case, when placing a loaded device on the seat). If it is impossible to set the seat in the middle position, then it is adjusted slightly, tilting up and back from the middle position. The suspension mechanism can be locked in the middle position. Non-adjustable suspensions lock in a vertical position when a fully loaded device is placed on the seat. The method for determining the CTS is as follows. The device (without additional masses) is placed on the seat cushion, previously covered with fabric to facilitate correct placement, and pushed back against the seat back. Additional masses are installed on the device, bringing the total mass from 6 ± 1 kg (device mass) to 26 ± 1 kg. The point of application of the vertical force created by the additional masses should be located at a distance of 40 mm from the projection of the CTS on the horizontal part of the device. The device, loaded with an additional mass, is pressed against the seat back with a horizontal force of 100 N. Then additional masses are installed on the device, bringing its total mass to 65 ± 1 kg. At the same time, the center of application of the vertical force from the additional masses should not change (the mass of the average operator of 75 kg corresponds approximately to the mass of the device of 65 kg placed on the seat). In two vertical planes drawn on both sides of the seat at equal distances from the longitudinal axial plane of the seat, the coordinates of the points of intersection of these planes with the axis passing through the one indicated on the CTC device are determined with an accuracy of ± 10 mm. Next, calculate the arithmetic mean values ​​of the results of the measurement of CTS in two planes.

To determine TOS and CTS, devices of different design are used. Methods for measuring these points differ in the force applied to the device: for TOS - 550 N, for KTS - 590 N, and in both cases the estimated weight of the operator is 75 kg. In addition, when determining the CTS, the position of the seat adjustments is clearly specified, while the position of the TOC can vary depending on the position of the seat adjustments.

Agricultural tractors with mounted earthmoving equipment are used in industry, so they must meet the requirements of standards for earthmoving machines. If there are two base points that differ both in devices for their determination and in the measurement technique, certain difficulties arise due to the need for two sets of documentation for workplace operator and double the amount of testing to determine the indicated points. As a compromise solution, taking into account the results of studies to identify the correlation between these points, the following relationship was adopted: the CTS is located 90 mm higher and 140 mm forward relative to the TOS. It is expected that as experience in using both points is gained, a single base point of the seat will be chosen. The definitions of TOS and KTS considered above are needed for designing a new cabin when upgrading a tractor. The design of a new cab, or rather, the operator's workplace, should begin with the choice of the position of the base point relative to the tractor's little-changing units, for example running system, transmission. With direct measurements of the operator's workplace, measurements can be taken from any point on the device, and then recalculated from the TOC. In 1986, the International Organization for Standardization (ISO) and the Organization for Economic Co-operation and Development (OECD), given the stability of the definition of CCC, decided to rework standards using the base point of the operator's workplace from TOC to CTC.

Cabin- this is the workplace of the tractor driver, where they spend most of their working time. Go to design tractor cabs impose the following requirements: rational placement of controls and seats; reliable protection against precipitation, sun, wind, dust, exhaust gases, negative temperatures, vibration and noise; good visibility; large margin of safety.

The cabin is usually made of all-metal with two hermetically sealed glazed doors. On tractors, it is installed on four shock absorber supports, which reduce the vibration of the tractor operator's workplace.

On the Figure 210 shown tractor cab T-150K. For thermal and noise insulation, vibration reduction, the floor, roof and front panel of the cabins are covered with insulating and sound-absorbing materials. The doors also have soundproofing gaskets and hermetically close the doorway thanks to rubber seals. The door windows are opened with power windows. Full opening of doors is limited by stops. Each door has a lock. Wide cab windows provide good visibility. Windshield wipers are installed on the rear and front windows. Fig.210. Cabin of tractor T-150K; 1 - a layer of mastic; 2 - cardboard; 3 - screen; 4 - power window handle; 5 - lock; 6 - handrail; 7 - shock absorber; 8 - buffer Cabins are equipped with a sun visor, rear and side view mirrors, a thermos for drinking water, a fire extinguisher, a tool box, a clothes hanger.

Cabins of general purpose tractors are equipped with seats for the driver and passenger with seat belts. On universal row-crop tractors, the cabs are single (the seat is only for the tractor driver).

Tractor seat ( rice. 211, a) is mounted on a suspension 4 of a parallel-gram type and sprung with a spring 2 or a torsion bar. To dampen vibrations, it is equipped with a hydraulic shock absorber 5. The tightening force of the spring 2 is adjusted by screw 1 in direct proportion to the weight of the driver.

On the MTZ-80 seat ( rice. 211.6) are bolted to the cab floor. The seat is single, with a torsion bar suspension and a hydraulic shock absorber. The design of the seat provides for its adjustment in height, length, backrest tilt and suspension stiffness. Rice. 211. Tractor seat: a- diagram of the device; 1 - adjusting screw; 2 - spring: 3 - bracket: 4 - suspension; 5 - shock absorber; b - seat MTZ tractor-80: 1 - length adjustment lever: 2 - handle for fixing the seat in height; 3 - lower arm; 4 - rubber stop; 5 upper lever: 6 - stiffness adjustment screw; 7 - backrest tilt mounting bracket.

Handle 2 changes the position of the seat in height within 0 ... 80 mm. By moving lever 1 to the left, you can move the seat forward or backward by 150 mm every 25 mm. Using bracket 7, the backrest is installed in three positions at different angles of inclination to the seat. Screw 6 regulate the stiffness of the suspension. In the free state, the suspension arms 3 should touch the rubber stop 4, and in the loaded state (with the tractor driver), the seat should lower by 60 mm, i.e., by half of its full travel. With a larger stroke of the seat, the screw 6 increases the stiffness of the suspension (turn the screw 6 counterclockwise), and with a smaller deflection, the stiffness is reduced.

The microclimate in the cabin must meet the following requirements: the air temperature during the warm period must not exceed the ambient air temperature by more than 2...3 °C and must not be lower than 14 and not higher than 28 °C; air velocity during ventilation - no more than 1.5 m/s; dust content in the air - no more than 2 mg/m3, carbon monoxide - no more than 20 mg/m3.

For forced supply ventilation of tractor cabs, a fan-dust separator is used ( rice. 212, a). It is installed on the cabin roof and consists of a housing, a hood 1, a branch pipe 2, a shield 3 and an electric motor 5 with an impeller 4. When the fan impeller rotates, air from the environment is sucked under the hood 1, enters the impeller blades and, after centrifugal cleaning, passes through the pipe 2 into the cab. Dust separated from the air, hitting the partitions, is thrown out through the outlet in the fan housing. Shield 3 regulates the direction of air flow into the cabin.

To ensure normal temperature regime in summer time cabs of some tractors are equipped with forced ventilation with an air cooler. Typically, water-evaporative type air coolers are used, the operation of which is based on the principle of heat extraction during the evaporation of water in contact with air. Such a ventilation unit supplies dust-free, humidified and cooled air to the cabin.

Ventilation unit with an air cooler of the tractor DT-75MV ( rice. 212b) works as follows. outside air through the air intake hood installed above the cabin roof, it is sucked in by a centrifugal fan 1 and undergoes centrifugal cleaning of dust, which is removed through the slots in the volute 2. Then the air passes through the central pipe 4 and is additionally cleaned of dust in the sump when the direction of movement changes. With the passage of warm air through the tray and grate 9, moistened with water from the tank 14, the water evaporates. The air is humidified, cooled and, passing through the cassette 8, is finally cleared of dust and water droplets. The purified air enters the cabin through the shield 5, which regulates the direction of its flow.

The water level in the sump is automatically set by a float valve 10, which closes and opens the hole connecting the cavities of the water tank and the sump. Water consumption is 1.2...1.4 l/h.

In the cold season, the cabin of the T-150K tractor is blown with air heated in the core of the radiator of the diesel cooling system. Air enters the radiator core through intake 1 ( rice. 213) through a metal sleeve 2. When leaving the cabin, warm air is directed through pipes 3 with slots to blow windshields, and through the outlet pipe 4 - directly into the cabin. A damper with a handle 5 is installed on the outlet pipe, when it is closed, all incoming air is directed to blowing the windows. The damper handle in the inlet pipe can completely block the air flow into the cab.

The cab is the part of the tractor in which the tractor operator is located during operation. It contains all the controls.

Working during the period of spring field work for 14-16 hours a day, the tractor driver must be in a comfortable and safe environment, where all the necessary indicators of noise, vibration, dust content, as well as a comfortable temperature and microclimate are met. The cabins of modern tractors make it possible to implement all these requirements and protect the tractor operator from the effects of the external environment.

The work of a tractor driver is not easy. In the process, strong shaking, a large amount of dust, high ambient temperature are inevitable. Therefore, the design of the cabin must fully meet all the requirements for the workplace of the tractor driver, for his working conditions. The hermetic design is important here, preventing the ingress of dust and moisture. The equipment installed inside the cab should create a comfortable temperature and microclimate in the tractor driver's work area, and a large glazing area will provide excellent visibility.

Mounting the cab to the tractor frame through rubber dampers reduces the level of noise and vibration transmitted from the engine and transmission during operation. Height adjustable seat and wheel tractor will allow you to comfortably accommodate both a short driver and a tall tractor driver.

Cabins that are installed on MTZ tractors are divided into two main types:

1. unified cabin UK;
2. small cabin MK, manufactured with a reduced overall height.

In conditions where the tractor is used mainly as a row-crop tractor, as well as in other cases where height does not play any role, unified cabins of the UK are used.

The convenience of the cab is in the large space above the head of the tractor driver, which in some cases is of no small importance. But very often the height of the cabin, and with it the entire tractor, is crucial. Such situations usually arise when the tractor is operating in various rooms. These can be warehouses, buildings for keeping livestock, as well as other buildings and structures. In such cases, machines with a small MK cabin are used. The installation of such a cabin reduces the overall height of the tractor by 300 mm - from 2850 to 2550 mm - and makes it easy to use it in more a wide range tasks.

In terms of interior arrangement, both cabins are practically the same. They are equally comfortable and convenient for the driver, they are interchangeable and the replacement of one type with another does not require any changes or alterations in the tractor design.

Construction and interior design

The cab of a modern MTZ tractor has a rigid frame and a fully sealed structure. It is attached through rubber shock-absorbing pads, which significantly reduces the vibrations that occur during operation. A heating and ventilation system provides a comfortable temperature and microclimate of the interior space, and if desired, you can open the sunroof located on the roof or the rear window. A comfortable fit for the tractor driver is ensured by a torsion seat with a hydraulic shock absorber, adjustable for the height and height of the driver.

The cabin is equipped with a sun visor, a lighting cover, as well as hangers for outerwear. Steps and handrails, as well as a reclining steering wheel, provide ease of boarding and exiting the car. The steering column also has a vertical adjustment, which allows you to choose a comfortable position for a tractor driver of any size.

Comes with a first aid kit and a water bottle. Also, MTZ tractors can be equipped with air conditioning, which is extremely important when working in the summer. Rear-view mirrors are located on the outer frame. With the help of a special device, it is possible to fix the tractor doors in the open position, which adds convenience when the driver gets into and out of the tractor.

Overview Above All

A distinctive feature of the cabs of MTZ tractors is excellent visibility. It is achieved with the help of a significant degree of glazing of its elements - a large windshield and side windows, almost completely glazed doors, a rear window, and even a sunroof. On the walls of the cabin there are additional viewing windows. Visibility is also added by large adjustable rear-view mirrors located outside the cab. In any situation, the tractor driver has the opportunity to see almost everything that happens outside, which is especially important both during field work and when working inside buildings and structures, when work is carried out in a limited space and the driver needs to “feel” the dimensions of the tractor with great accuracy.

Sizes of glass tractors Belarus MTZ-80/82
Tractor model	Cabin	Type	Dimensions, mm
MTZ-80	old	Frontal	1044x656
	New	wind	1245x915
	New	Wind bottom	434x278
	old	Wind rear	1040x655
	New	rear	1195x840
	New	Lateral	770x640
	old	Lateral	765x630
	New	Door	765x600
	old	Door	630x450
	MK	Lateral	475x225
	MK	Door	659x453
MTZ-82	UK	Lateral	767x642
	UK	Lateral	868x749
	UK	Door	763x608
	UK	rear	1205x841
	UK	Front	1267x921

The design of the MT3 tractor cab makes it possible to almost completely eliminate "blind" visibility zones for the tractor driver and provide excellent visibility in all directions. During precipitation, electric-type windshield wipers installed on the front and rear window cabins. They have several modes, from which you can always choose a convenient one, depending on the intensity of precipitation. Heat-absorbing glass is used for cabin glazing, which helps to avoid excessive heating of the air inside the cabin during the hot season.

Interior decoration

In the manufacture of MTZ tractor cabins, modern high-quality and environmentally friendly materials are used. This applies both to those materials from which the supporting part of the frame is assembled, and materials for interior decoration. The cabin is made of sheet steel and has a frame structure. The strength of materials and accurate design calculations ensure the safety of the tractor driver in critical situations, such as tipping over and even overturning the tractor.

It is also important what materials are used for interior trim of the tractor cab. For its arrangement, modern noise-absorbing and heat-absorbing materials are used, which sheathe the interior of the cabin. There are rubber mats on the floor to fix the legs in the desired position and prevent them from slipping off the pedals.

All materials used in the manufacture of cabins are certified and comply with the requirements of environmental standards and are safe for the life and health of service personnel. The materials from which the interior trim elements are made have neutral gray colors that do not irritate the eyesight and do not distract the tractor driver from his work.

We control the parameters

To control the operation parameters of all the main components, assemblies and mechanisms of the tractor, the instrument panel is used. It is located on the front panel of the cab right in front of the tractor driver's eyes and includes a standard set of instruments and warning lights. These are a speedometer, an oil pressure and engine temperature gauge, on-board electrical network control devices and others.

The gauges have the familiar round shape and are arranged in an easy-to-read combination. A cursory, experienced look at the instrument panel is quite enough to adequately assess the parameters of the tractor systems. The exit of any indicator from the permissible limits is immediately signaled by bright signal lamps, which make it possible to make a decision to stop the operation of the machine and begin troubleshooting.

For work in the dark, the instrument panel has a light illumination, when turned on, the instrument readings are easy to read. All devices are pointer type with a scale divided into zones. Under normal operating parameters of the tractor mechanisms, the arrows of the instruments should be in the green zone of the scale. The exit of instrument arrows from the green zone indicates deviations in the operation of the tractor. In this situation, work is stopped until the malfunction is clarified and eliminated.

Governing bodies

The most important in the convenience and safety of driving the tractor is the correct and convenient location of the controls. This applies both to the control of the main working operations of the tractor, and auxiliary functions, such as headlights, control of windshield wipers, interior heating and others. On the cab floor are the brake pedals, clutch pedals, and the accelerator pedal. The control pedals are equipped with rubber pads that secure the foot and prevent it from jumping off, which is an important detail in terms of safety.

To the right of the driver are the levers for controlling the working operations of the tractor. They are located ergonomically and conveniently, which increases the accuracy of controlling mechanisms. For clarity, before the driver's eyes there is a diagram of the purpose of the levers, combinations of their positions and combinations.

The steering wheel is a comfortable size, fits well in the hand and has a horn button in the middle. Below the steering wheel are the turn signal switch and the windshield washer switch. The controls for auxiliary functions of the tractor are also conveniently located. The switches are located on the instrument panel in an easily accessible place and have a light indication of inclusion.

Microclimate

The microclimate in the tractor cabin is of particular importance. During the summer at permanent job tractor in the open air, the temperature inside the cabin can reach 50-60 degrees Celsius. The air conditioner significantly lowers the temperature in the cab to an acceptable 23-25 ​​degrees, providing comfortable conditions for the tractor driver. To clean the air entering the cabin, a modern multi-stage filtration system is used. This is extremely important, since during field work there is a significant amount of dust outside the tractor, which can often contain chemical elements harmful to the respiratory tract. This applies to work with fertilizers, chemicals for pest control of others.

The air conditioner has two main versions:

• engine compartment;
• roof.

During work in autumn-winter period the air inside the cabin, on the contrary, must be warmed up to a comfortable temperature. A powerful stove connected to the tractor engine cooling system perfectly copes with this task. The stove has several modes of operation, which allows you to set the desired temperature, regardless of the weather overboard. Also, the stove performs another important role - preventing the windows from fogging during precipitation in the form of rain and snow. In the warm season, the stove can be disconnected from the cooling system using a special tap.

Dismantling

Sooner or later there are cases when it is required to dismantle the tractor cab. This may be necessary both for repairing the cab itself, and for gaining access to some tractor units and assemblies, such as rear axle, gearbox, clutch and others. The cab is also removed if it is replaced with a new or similar one.

Dismantling the cab of the MTZ tractor is a rather laborious process, therefore it should be carried out by specialized repair enterprises with the necessary equipment and qualified trained personnel. But if necessary and the availability of lifting equipment, this work can be done independently.

The procedure for carrying out work on the removal and installation of the cabin is described in detail in the repair documentation for the tractor.
To dismantle the assembly, it is necessary to remove the rear radiator cover and disconnect the control rods. After that, the control pedals are dismantled and the cab mount to the brackets is dismantled. Then disconnect the starter wire and disconnect the instrument panel.

Next, remove the gearbox and reduction gear handles, remove the handles from the control levers of the reduction gear and gearbox. Then the tachospeedometer cable, signal wires and headlights are dismantled. After removing the floor mat and box, you need to start removing the fuel pedal. After that, the floor is removed. To do this, the fixing bolts inside the cab and from below are first unscrewed. Next, the sector and the lever of the power regulator are removed. Then, disconnecting the wires and removing rechargeable batteries, the tractor cab is removed by the lifting mechanism. After the repair work the cabin is installed in its original place in the reverse order.

Repair

During operation, it is necessary to carefully and attentively monitor the condition of the tractor cab, timely carry out the necessary Maintenance. At the same time, much attention is paid to the condition of metal parts and paintwork. Minor scratches and other damage must be removed immediately to prevent corrosion. You should also periodically carefully inspect the glass seals for leaks. Damaged seals are immediately replaced with new ones.

You should periodically pay attention to the state of heat and sound insulation. Do not operate cab with broken or cracked glass. Such glasses must be replaced with new ones. Tractor door hinges must be periodically lubricated with grease.

Repair of the cab of the MTZ tractor after damage as a result of accidents or overturning of the tractor should be carried out in specialized repair shops with the appropriate equipment. Such workshops can also advise on the suitability of a damaged cabin for repair and the feasibility of replacing it. small cosmetic and technical repair tractor cabs can be made on their own due to the good maintainability of MTZ tractors even in the field. During the work on the removal and installation of the cab, it is necessary to be guided by the documentation for the tractor, as well as strictly observe the requirements of safety regulations when performing these types of work.

The working conditions on the tractor largely determine the productivity of the MTA, because due to the increase in the energy saturation of the tractor, the speed of technological and transport operations, the number of machines and implements aggregated with the tractor, the functional activity of the tractor driver becomes more complicated. Thanks to the rational design of the tractor control station, it is possible to significantly reduce the fatigue of the tractor driver, relieve him of inconvenience in work, increase labor productivity and, most importantly, reduce the risk of general and professionally caused morbidity.

The tractor cab with the appropriate equipment must protect the tractor driver from serious injuries in case of accidents, reduce the level of noise and vibration, have good visibility, convenient entry and exit, as well as the placement of controls and seat. The microclimate in the cabin must be maintained regardless of changes in external conditions. The ventilation system must supply air purified from dust and harmful impurities.

The cabin determines the composition and nature of the shaping of the machine as a whole. A rationally designed cab that creates comfortable working conditions for the tractor driver requires significant material costs. Suffice it to say that the cost of a modern tractor cab is 40...50% of the cost of the machine as a whole.

16.1. Protective cabin designs

One of the most serious hazards that a tractor operator is exposed to is the possibility of injury when emergency. So, for wheeled agricultural tractors of the classic layout, tipping to one side is typical, while the tractor can make several revolutions. Industrial tractors are characterized by side tipping over the roof of the cab and falling stones on the roof when working in quarries or mining. For caterpillar forestry tractors, there may be cases where trees, twigs and branches fall on the cab.

A wide variety of design solutions for cabin protective devices are classified according to their design and the number of vertical load-bearing elements. At the same time, two - and many

Rack-mounted (four- and six-rack) frames can be built into the cab or located outside of it in the office. In addition, cabins are classified according to their technical design into stamped, frame and combined.

An example two-column frame, on which the remaining elements of the cabin fencing can be fixed, is the design shown in fig. 16.1. On the axle housing rear wheels the tractor is equipped with racks 6 and 7, tilted back so that their upper ends are above the rear of the tractor driver's seat. The cross section of the upper ends of the racks is less than the cross section of their base.

Rice. 16.1. Protective fence of the workplace of the tractor driver:

a - a rigid two-rack frame with a roof; b - installation of a rigid frame on the tractor; c - installation of a cab with a rigid two-column frame on a tractor.

The design has a horizontal cross member 5, which fastens the upper ends of the uprights and serves to install the roof 4 with cross bars 1 and 3 and longitudinal braces 2 and 8. To crossbar 1

the front wall of the cabin 9 is attached, to the longitudinal links 2 and 8 - the side walls 10 and 11, and to the cross member 5 - the rear wall 12 of the cabin. Thus, having a two-post frame with an upper crossbar as a rigid element, it is possible, by hanging additional elements on it, to obtain an awning or a closed cab on the tractor.

Such devices, which were previously widespread especially abroad, have significant disadvantage: the floor of the cab is the upper part of the transmission housing, which causes a significant noise level in the workplace. Currently, similar two-post frames with a protective roof are used only on industrial tractors to protect the cab from falling objects.

On agricultural tractors are widely used multi-column protective cages, which, when installed

ke form a supporting element for the cabin panels fixed on it. The rigid frame is formed by the cabin body, which is made in the form of a single unit mounted on the tractor with the help of rubber vibration isolators, and the opaque panels are lined with heat and sound insulating materials from the inside. At the same time, the cabin body can be made of stamped elements and from profile and plate rolled products.

On fig. 16.2 shows the body of the cab of an agricultural tractor, made of elements stamped from steel with a thickness of 1 ... 1.25 mm. Body parts - front 1, left 6 and right 2 side panels, roof 3, left 5 and right 4 racks, rear panel 8, left 7 and right 9 sills are assembled into a common assembly by welding in the assembly jig. This technology is widely used in the automotive industry and provides high accuracy and the required quality of cabin manufacturing at a relatively low cost in large-scale production.

On fig. 16.3 shows the design of the cabin body, made of thick sheet metal. The cabin body contains two rigid belts, one of which is formed by a bent profile 10 of the base, side profile racks 8 and 12 and a profile jumper 6, and the second - rear pillars 4 and 15 , jumper 2 , sidewalls 3 and 16 and rear roof cross member 1 . Both rigid belts are connected by longitudinal links 5, 7, 13, 14 and form a closed system, to which the front panel 9 is attached, formed from profiled rolled products and parts bent from a sheet. Floor 11 made of sheet steel is welded to the bottom trim of the frame.

Rice. 16.2. Cabin body and stamped elements:

a - general view; b - constituent elements

Rice. 16.3. Cabin body made of plate

Rice. 16.4. Cotton-growing tractor with frame cab

A frame cabin made of standard rolled rectangular tubular section is used on the T-25A tractor and cotton-growing tractor (Fig. 16.4).

Six vertical tubular racks of rectangular section of the cabin frame are connected by longitudinal and transverse beams. Thus, three vertically mounted closed frames are interconnected. The rigidity of the frame connection is increased by installing gussets stamped from sheet steel. The cabin is equipped with sliding doors and has relatively large glazing (64%), with the entire front frame glazed. The windows are installed on the cab frame with the help of special rubber seals.

Advantages of frame cabins compared to cabins made of stamped elements are:

less cabin weight due to the use of non-metallic materials for fences;

less metal consumption by 30…40%; simplification of cabin modification depending on the demand for

Specified positive traits frame cabins with the use of standard rolled products in the design led to their wide distribution on tractors.

The disadvantages of cabins of this type include the increased complexity of assembly and welding of the hull due to the complexity of welding automation.

In case of particularly severe accidents, when the tractor can roll over more than 180° when falling, there is a danger of the tractor driver being thrown out of the cab, as a result of which he can be crushed by the tractor. For the

To increase safety, glazed openings of the cab are sometimes enclosed with a metal mesh, which protects the tractor driver in the cab from penetrating objects. In order to protect the tractor

christ from ejection from the cab sometimes use seat belts (such as automobile).

When working on the ice of frozen reservoirs, it may be necessary to quickly exit the tractor driver from the cab. For this purpose, an emergency hatch is provided in the cab roof (see Fig. 16.2). In the event of a tractor overturning, if there is no hatch, the tractor driver can get out of the cab into any cabin opening convenient for this, since the glass from stalinite usually crumbles in such an accident. In accordance with GOST 12.2.120, glazed windows are emergency exits. Therefore, there must be means in the cab that can be used to break or expose the emergency exit glass in an emergency.

On industrial tractors, in accordance with GOST 12.2.121, the design of the machine must provide the possibility of installing, at the request of the customer, protective devices that ensure the preservation of the deformation limitation volume (safety zone in the cab) in case of accidental falling objects on the cab or when the tractor rolls over. Unlike an agricultural tractor, the cab of an industrial tractor should not have a rigid frame designed for cases of machine overturning. The protective device is located outside the cabin (Fig. 16.5).

Rice. 16.5. Protective device and cab of an industrial tractor:

a - protective device; b - cabin

The protective device contains a U - shaped detachable frame made of a rectangular section profile, to which a protective visor is attached from above. The lower ends of the racks of the U - shaped frame are attached to the tractor frame. The cabin is also attached to the tractor frame and is covered from above with a protective device.

5. The parameters of visibility through the wind window and the standard field of view are determined.

6. Rear-view mirrors are placed, and visibility through them is provided.

7. They proceed to the next stages of designing the interior of the cabin: the instrument panel, seats, interior elements are assembled, as discussed below.

2.3. The layout of the workplace of the tractor driver

The layout order of the tractor driver's workplace methodically differs from the outlined order of design work on vehicles.

The machine-tractor unit is controlled by one driver (operator). Therefore, in most cases it is sufficient to install single cabs on tractors. Some firms install a removable passenger seat on request.

The minimum dimensions of single cabins are normalized, mainly the width and height. At the same time, the anthropometric data of the driver of the 95th level of representativeness are guided. The length of the cab is not regulated, since it largely depends on the layout of the tractor.

When arranging the workplace of the tractor driver, first of all, it is necessary to determine the minimum dimensions and geometric shape of the surfaces that limit the space inside the cab around the operator located on the seat in a comfortable working position. These parameters are set by the standards. It is impossible to change the limiting dimensions down, and they are usually increased, because the cabin provides space for outer clothing, a first aid kit, a thermos with water or food, and sometimes for a second seat.

The internal dimensions of the cabin are set from the control reference point of the seat (CTS) in accordance with GOST 27715-88. Minimum dimensions single cabs and cabs with an additional seat, designed to work while sitting, for agricultural and forestry tractors are shown in fig. 2.19 and are regulated by GOST 12.2.120-88, and for industrial tractors in fig. 2.20 (GOST 12.2.121.88).

GOST 12.2.120-88 establishes the dimensions of single and double cabins of agricultural and forestry tractors (Fig. 2.19). For a single cabin, the minimum height is 1010 mm, the minimum width is 900 mm at a height of 310 to 810 mm from the horizontal plane passing through the CTS. The width of a double cabin at the same height must be at least 1400 mm. The distance from the vertical plane passing the seat reference point (TOS) to the rear wall of the cabin must be at least 365 mm. On fig. 2.19 also shows the minimum distance from the steering wheel to any structural elements of the cab.

Structural elements that ensure safe entry and exit from the tractor cab include the following: doorway and cab doors, steps, handrails, emergency hatch. The cabin fully meets the safety requirements for entry and exit with the following parameters:

- cabin floor height from the supporting surface 1008 mm;

- doorway height 1600 mm;

- doorway width 400 mm;

- width, depth and height of the step above the level of the supporting surface, respectively, 300, 100 and 520 mm;

- distance between the floor surface and the level of the last step 316 mm;

- step angle outward 55…65 about .

IN in accordance with the requirements of international standards (ISO) and domestic standards, tractors must be equipped with steps and (or) ladders with the obligatory presence of handrails and (or) railings. The location, dimensions, requirements for the materials of these elements are specified by the standard. Structural elements of other purposes can be used as intermediate steps.

On fig. 2.21 shows the values ​​of the parameters that regulate the requirements for driver access to the workplace. Distance between edge

of the door opening and the seat cushion must be at least 300 mm with an average seat position according to the adjustments.

The standard sets the dimensions of the doorway with the maximum possible opening of the door (Fig. 2.22). If the operator works while sitting, then the height of the doorway must be at least 1300 mm, and if in a standing position - 1800 mm. The shaded area in Fig. 2.22 refers to a cab where the operator is seated. If the doors open less than 90o, the dimensions of the doorway must be increased so that the clear dimension corresponds to that indicated in Fig. 2.22.

	Rice. 2.21. Minimum values
		Rice. 2.22. Door dimensions
	workspace access settings
		opening according to GOST 12.2.120-88
	place of the tractor driver

The tractor cab must have at least three emergency exits, which can be doors, windows, hatches, and each exit should be placed on opposite sides (walls, roof) of the cab. This requirement is important to comply with in order to increase safety in case of overturning of the tractor and jamming of doors. The dimensions of emergency exits must correspond to the dimensions of the doorway or be at least: 600x600 mm for a square section; 470x650 mm for rectangular; 700mm in diameter for round; or in the form of an ellipse with main axes not less than 640 and 440 mm. Emergency exits must open without the use of a tool. Cabin windows, if they are intended for emergency exit, must be equipped with means for breaking or promptly dismantling glass.

On fig. 2.19 and fig. 2.20 there is no data on the longitudinal dimensions of the cabin at floor level. This is due to the following circumstances. Firstly, at different seat heights for a comfortable working posture, the operator

The rider requires a different distance to the pedals: with a low seat it increases, with a high seat it decreases. Secondly, operators have different anthropometric characteristics, and for the convenience of their work, the position of the seat must be adjusted in the longitudinal direction by ± 75 mm, vertically by ± 40 mm relative to the middle position, which also does not allow you to rigidly set the longitudinal dimensions.

The location of the main tractor controls is shown in fig. 2.23. The vertical and horizontal dimensions that determine the relative position of the seat and the centers of the clutch and brake pedals are given below:

The position of the steering column must be adjustable in the longitudinal direction (along the installation angle) and in height (along the axis of the column) by 100 ± 20 mm steplessly or with fixations in at least four positions in angle and five in height.

Rice. 2.23. Mutual arrangement of the seat and the main controls of the tractor:

1 – a steering wheel; 2 - clutch pedal; 3 – brake pedals; 4 - fuel supply pedal

The supporting platforms of the main pedals must have a length and width of at least 60 mm, the distance between the edges of the platforms of non-blocking pedals between themselves - 50 ... 100 mm, blocked - 5 ... 20 mm. The angle of turn of the supporting platforms of the pedals driven by the foot must not exceed 15° from the longitudinal plane of the machine.

The distance from the handles of the levers in any position to the elements of the interior and to the neighboring levers must be at least 50 mm (if the levers are driven by a brush) and at least 25 mm (if they are driven by the fingers). If the levers are moved simultaneously with two hands or it is supposed to work in mittens, as well as in the absence of visual control over the position of the levers, the distance between the levers located nearby and controlled by the hand increases to 100 ... 150 mm. Of course, the handles of the controls, especially the movement controls, must be located within the reach of the operator. In this case, the bending angle of the operator's arm in the elbow joint should be close to 135°, and the force should be applied in the direction "directly towards you - away from you." When operating the levers of precise and continuous control in conditions of significant vibrations and fluctuations, especially low-frequency ones, it is necessary to provide support for the hands, for example, armrests.

Visibility from the tractor operator's workplace is of particular importance, because many technological operations performed with the help of tractors require very precise positioning of the machine's working bodies, wheels and tracks relative to other objects, as well as precise maintenance of the machine's trajectory. The viewing angles of functional zones and objects of observation are taken as the main evaluation indicator.

As a reference point for the visibility parameters for agricultural tractors, the point K was taken, which has the coordinates: 670 mm up and 10 mm forward relative to the seat control point (CTS) in the longitudinal vertical plane. Its position mimics the position of the operator's eyes. The angles that determine the visibility of an agricultural tractor from the cab in accordance with GOST 12.2.019-86 are shown in fig. 2.24, and their values ​​are given in table. 2.5.

For tractors and self-propelled agricultural machines, the visibility of the front wheels or the front parts of the tracks is of particular importance. These parameters are also stipulated by the standard.

Rice. 2.24. Angles that determine the visibility of an agricultural tractor in accordance with GOST 12.2.019-86

Table 2.5 Viewing angles through the windows of the cab of an agricultural tractor

	Designation			Traction classes of tractors
View area				wheeled*		caterpillar
	viewing angle					all classes
					Viewing angle, hail
Front
	β1**
	β4***
Front (che-
cut the cleaning zone
ki glass-

* For tractors of traction classes 5 and higher with a seat shifted to the right, the viewing angles must be at least: α 1 =600 to the left; α 1 =250 to the right; γ 2 \u003d 350; γ 4 \u003d 200.

** For tractors performing transport work on public roads.

*** It is allowed to reduce the angle to 20° for tractor self-propelled chassis with the engine located behind the cab.

	For tractors universal
	tilled and general purpose
	(for each type separately) pre-
	are additional requirements
	in accordance with the technology
	cal appointment. Yes, for
	universal tilled tractors
	the ditch must be provided with
	bridge of points 1 and 2 as shown in
	rice. 2.25. This is due to the specific
	which move the tractor between
	fools cultivated culture
	ry. Distance 250 mm between
	points 1 and 2 guarantees a good
	clear visibility of the protection zone.
	On wheeled tractors
	general purpose traction classes
	3 ... 5 review of section A is mandatory
Rice. 2.25. Visibility zones of points	(Fig. 2.26) the area in front of the front
tractor front wheel clearance	him with a wheel, and in caterpillar
	tractors of traction classes 2…5 –

review of the front of the caterpillar (point 1) and section A (Fig. 2.27) of the area in front of the caterpillar. In this zone there is a furrow, relative to which the movement of the general purpose tractor is directed, or another landmark, depending on the operation being performed.

Rice. 2.26. Scheme of visibility of section A in front of a wheeled tractor

R= 17000 mm)

Rice. 2.28. Panoramic visibility scheme (for wheeled tractors class 5 and above

Rice. 2.27. Scheme of visibility of section A ahead caterpillar tractor and dots 1 on the front of the caterpillar

In many cases, special windows are installed in the lower part of the cab or tractor doors to ensure visibility of these areas.

When using tractors for transport work on general roads, they are subject to UNECE rules, according to which no more than two invisible sections are allowed within each sector (1, 2, 3) outside the circle of radius R (Fig. 2.28). Width B of the invisible section in sector 1 (at radius R) should not exceed 700 mm, and in sectors 2 and 3 - 1200 mm.

In each of sectors 2 and 3, it is allowed to increase the width B of one of the sections up to 1500 mm, but the width of the other invisible section should not exceed 700 mm. The presence of such visibility requirements predetermines the width of the cabin and frame elements.

For industrial tractors, based on the specifics of their work, forward visibility is determined from the point K 1, and backward - from the points K 2 and K 3, the location of which relative to the CTS is shown in Fig. 2.29.

Rice. 2.29. The location of the reference points for the visibility of the industrial

tractor with respect to KTS Fig. 2.30. Industrial visibility parameters

lazy tractor (angle values ​​- in table. 2.6)

The presence of three points and their location is explained by the fact that the operator of, for example, a bulldozer must look forward for almost half the time the tractor is working, and the other half, when reversing tractor - back, turning over the right or left shoulder, while the operator's eyes are approximately at the points K 1 and K 2.

The front view area is determined by the angles α, γ, α 2, γ 1 and γ 3 with a vertex at the point K 1 (see Fig. 2.30), and the back one - by the angles α 1 and γ 2 with vertices at the points K 2 and K 3. In the front view area, the operator must see point 1 located on the upper part of the track contour, and the section of the caterpillar at this point (shaded) with dimensions of at least b α

Front view side:

additional, γ 1

preferential:

45**

α1 *

* Towards the ripper tooth.

** Except tractor with front cab.

When operating an industrial tractor, the operator must be able to see the surfaces and objects shown in fig. 2.31. The numerical values ​​of the quantities indicated in fig. 2.31 are given in the standard.

Rice. 2.31. Objects of observation of the operator of an industrial tractor:

L is the longitudinal base of the tractor; B - transverse base of the tractor; S - blade width