Working principle of an excavator. How to operate a wheeled excavator

07.04.2019

Fuel system

30.03.2016

Single bucket excavators are machines with cyclical action, because due to the presence of only one bucket continuous work becomes impossible, and therefore excavation-transfer of soil is carried out cyclically. This somewhat reduces labor productivity compared to multi-bucket counterparts. However, in view of the versatility of use and the possibility of installing special nozzles that expand the capabilities of this special equipment, it is in steady demand when performing various kinds. Most often, excavators are used in conjunction with other special equipment. For example, during the construction of roads, they produce a dump of waste soil.

How does a single bucket excavator work?

Any single-bucket model consistently performs:

scooping up soil with a bucket;
transferring it to Right place where the unloading will take place;
bucket overturning, accompanied by spillage of soil.

This equipment consists of three main components:

running gear;
turntable;
specialized equipment that allows you to perform a certain type of work.

By using undercarriage ensure the movement of cargo. It receives and transmits the load from the machine. With modern special equipment chassis there are three types:

caterpillar. The traditional option, which, however, is not suitable for use in the city. Such cars cannot navigate the tracks on their own;
pneumatic wheel;
wheeled, ideal for the city. So wheeled Hyundai model R 170W-7 can move on the roads of various purposes on a par with conventional cars.

The rotation of the platform is provided by a slewing device. Typically, the rotation is 360 degrees. However, there are also part-turn machines that are not able to make a full turn.

In addition to the standard on modern models can be installed optional equipment, allowing to significantly expand the possible area of their use. It can be, for example, a hook or .

Depending on the type of suspension, the division is made into models with:

flexible. In this design, the arrow is fixed on the ropes;
tough. Work is carried out through the use of a swivel joint. The equipment is driven by hydraulic cylinders;
telescopic boom.

In addition to cyclic machines, excavators are produced continuous action. Due to their design, they are able to work continuously. Such special equipment throws the soil to the side, creating a dump. This type excavator can be rotary and chain. Most often, this technique is used in the construction of roads or after a snowfall.

In the latter case, the buckets are located on a single-row or double-row chain. Rotary buckets have a rigid rotor rotated by special rollers. At the moment of rotation of the rotor, the soil or snow is taken by a bucket with teeth, and it is unloaded onto a special conveyor belt for moving to the dumping site.

With a sufficiently high productivity of special equipment of cyclic action, it cannot be called universal. Therefore, our company offers products suitable for work in various conditions.

Hydraulic excavators are considered the fundamental machinery in the production a large number species from earthmoving or when performing work on moving masses of various kinds of soils. Based on statistics, the growth in the excavator equipment market is 7-8 percent annually. At the same time, imports of equipment from abroad show quite a good growth of 40-45 percent of this number. It turns out that the whole market is divided earthmoving equipment between foreign and Russian manufacturers.

To the question of which excavator is better when choosing, no expert will be able to give a definite answer. The arguments here are simple: cheaper Russian technology, and the western one is more reliable. Therefore, let's try to understand the question: how to work correctly on an excavator, so when neat work equipment breaks less often, but ignorance of control functions can result in an unambiguous breakdown.

Import equipment management

Now let's answer the detailed question: how to work on imported production excavator so as not to break it. First you need to decide: which one you will not have hydraulic excavator- small or large, you will need skill and practice to control it, but physical strength will not require accuracy. There will definitely be a dashboard, like a car good car, which will provide the necessary information about all the parameters of the machine. Present on it:

Hours counting board
Excavator fluid level
Alarm indicator - overheating warning
Charging excavator batteries
Engine temperature
Show oil pressure
tachometer

The excavator control functions will be shared by two joysticks, one will be responsible for the movement of the excavator in space and the movement of the near part of the boom, the other for the work of the bucket and the manipulator boom. No matter how difficult the job, management will require practice, which can be obtained on a computer with a simulator program for this type of excavator.

It is necessary to know that different types excavators, depending on the manufacturer's plant, have individual control schemes.

Management of domestic equipment

Control Features Russian assembly excavator will differ from imported machines by the presence of up to six hydraulic distributors connected directly to the hydraulic cylinders of the excavator boom manipulator, as well as the bucket control mechanism.

Will be responsible for forward movement equipment two pedals and a steering wheel for a pneumatic chassis or levers for tracked vehicle. Well theoretical training, and Internship will be the answer to the question of how to properly work on a domestically assembled excavator.

The process of digging a trench with an excavator

Digging a trench is the most popular type of excavation work. They dig trenches for laying cables, heating, sewerage, plumbing, etc.

In each case, the length, width and depth of the trench will be different, but remain general principles unchanged. Next, we will look at the basic rules for digging trenches, pits and ponds, as well as provide specific advice for individual situations.

Excavation with an excavator

Several stages include the excavator operation cycle:

setting the bucket to repeat the cycle
platform reverse rotation
bucket unloading
platform turn
soil cutting

The speed of work execution directly depends on the execution time of one cycle, more than half of which falls on platform turns. Thus, reducing the angle of rotation of the platform significantly speeds up the digging of the trench.

When cutting soil, the engine must be running at full power. The immersion of the bucket should be started as close as possible, and its contents should be poured out at the farthest point of the car body or platform, which is specially reserved for the mined soil.

The greatest efficiency is achieved when the depth of digging allows you to fully load the bucket. The optimal digging radius (the distance from the body of the excavator itself to the place where the bucket is immersed) is approximately 70-90 percent of the maximum, which is indicated in the technical documentation.

To reduce fuel and time costs even more, several operations are combined. For example, you can simultaneously turn the platform while lowering the bucket for subsequent digging or raising the bucket for unloading.

Digging trenches, pits, ponds

First of all, it is necessary to clean the face (the site where the work is being done, there is an excavator and additional equipment), from stumps, large stones, debris and any other unnecessary objects.

If it is necessary to transport the soil over a long distance, then the contents of the bucket are poured into the body trucks. Counts optimal situation when placed in the back of a truck 3-7 full buckets. The body is filled from the side or rear, movement over the bucket cab is prohibited. Filling should be done evenly, but the bucket is not allowed to level the contents of the body.

The excavator must be placed at a distance of at least one meter from the edge of the trench. The deeper the trench and the softer the soil, the further the equipment is located. A safe distance is recommended, which exceeds the digging depth by one meter, while the excavator is positioned so that the driving pair of wheels is further from the edge than the driven one.

The digging of an artificial pond requires a preliminary study of the soil and the depth of the direct location of groundwater. highly undesirable for similar works apply old equipment, it will not be possible to save in this way, but to get a large amount of expenses - completely. The most correct and reasonable option is to use an excavator that is able to work at a great distance, this will save nerves and equipment.

When digging deep trenches and pits, general rule: the greater the depth, the more gentle the slopes. If necessary, strengthen the walls.

If work is to be done in the wetlands, then special shields are taken with them, from which the working platform should be assembled. The length of the tracks themselves must exceed the size of this platform.

Compliance with work rules office instructions and safety precautions makes it possible to avoid unexpected situations, material damage and damage to equipment during operation. It will not be superfluous to draw up a contract for the performance of work in a certain amount.

Safety

When working on excavators of domestic and foreign production, it will be necessary to familiarize yourself with the safety instructions, which are developed directly for a specific model.

Before starting the first work, it is necessary to familiarize yourself with the meaning of the special information that is located on the units and the body of the excavator. In all dangerous places there will be warning signs on the machine, and have accompanying inscriptions that indicate the degree and level of danger possibilities:

Warning, will signal the possible likelihood of a potential danger, due to which non-acceptance necessary action result in potentially minor or moderate injuries.
The warning is intended to draw attention to the potential for quite dangerous situation, which can result in serious injury or death if precautions are not taken necessary measures.
Danger, signals the inevitability of a particularly dangerous event, in which case the neglect of the necessary safety measures can lead to serious injury or death.

The plates, which are found on all excavators, use inscriptions and drawings for visual warning and are mandatory for execution.

Do not confuse safety signs with information inscriptions on the rules for operating an excavator. It is necessary to use all knowledge to avoid accidents and to correct operation on the excavator.

Before starting work, the operator (driver) of the excavator must receive:

The most accurate indications of working conditions (the presence of obstacles, the location of overhead power lines, the presence of underground utilities and their places of passage, etc.).
Technological map of the excavator.
Safety instructions (enacted by order of the construction department).

Before starting work on the excavator, the driver must:

make sure the machine is in good working order; it is forbidden to work on a faulty excavator;
make sure that all rotating parts - gears, chains, belt drives, flywheels, etc. - are protected by covers or inaccessible to workers; it is forbidden to work on the excavator with the guards of moving or rotating parts removed;
check signal status; it is not allowed to start work with a faulty signal;
receive from the driver handing over the shift information about the presence of any malfunctions on the excavator and achieve the elimination of these malfunctions;
make sure you have the correct tool.
make sure of the strength of all connections (key, wedge, bolt, etc.), as well as connections of pipelines of control systems and, if necessary, strengthen them;
check the serviceability of the brakes and ropes; to Work with faulty brakes and ropes is prohibited;
check the serviceability of the control levers and set them to the neutral position;
lubricate the excavator in accordance with the lubrication chart given in the operating instructions for the excavator.

Only after the driver is convinced that the excavator is in full working order, he and other maintenance personnel begin refueling the excavator. In this case, the following safety requirements must be observed:

refuel the engine and hydraulic system with fuel and oil only in natural light; in extreme cases, you can refuel at night, but with electric lighting;
while refueling the car, it is forbidden to smoke, use matches, kerosene lamps and other sources of open fire;
after refueling the excavator, all parts doused with fuel or oil must be wiped dry, and fuel spilled near the excavator should be carefully covered with sand;
it is forbidden to open a barrel of fuel by hitting the cork with a metal object;
fuel that has ignited near the machine must not be extinguished with water; to extinguish ignited fuel, you should use a fire extinguisher, which must be on the excavator, as well as sand, tarpaulin, etc.

Safety requirements when starting the engine and during its operation

Before starting the engine directly, the driver must make sure that it is in good condition, as well as that all engine starting devices are working:

engine, as well as liquid fuel starting motor must not have leaks of fuel, oil and water, as well as gaps exhaust gases in the connections of the suction and exhaust pipes with the engine block;
compressed air cylinders and their fittings of pneumatic starting devices must be in full working order; leakage of compressed air is not allowed;
the electrical wiring and the starting button of the electric starter must be in perfect working order; when the button is pressed, the electric starter should immediately turn on; current leakage in wires and terminals, as well as sparking, are not allowed;
the levers of the liquid-fuel starting engine mechanisms should switch easily and reliably; at a positive outside temperature, the starting engine should start easily.

The excavator driver himself must start the engine.

Construction is quite difficult process, which involves quite a few different types of work. Among them, a special place is occupied by tillage, which is carried out in most cases by excavators.

These mechanisms are quite expensive, so not every consumer can afford to buy it. An alternative is the usual rental of an excavator for a certain time, which makes it possible to complete all the tasks.

Preparatory work

The excavator is very complex mechanism, so its management will not be easy and requires certain skills. Before starting this process, you should follow a few simple recommendations:

First of all, you need to familiarize yourself with the system of the machine itself. It is necessary to single out the working bodies and structures to control them.
Before starting work, be sure to check that the excavator is working. To do this, it should be inspected for damage and other similar defects.
After that, be sure to read the operating instructions. This will help you deal with all the buttons, levers and other elements.

Getting Started

The excavator control process should begin with the following simple recommendations:

First you should get behind the wheel and start the engine so that it warms up for a certain time. Also, make sure that all working parts are on the ground.
After that, let go parking brake and try to move forward on the excavator. In this case, it is advisable to immediately use only low speeds in order to get used to the operation of the device.
The next step is to study the work of the main organs. They can be controlled both with the help of levers and joysticks. Raise the bucket slowly, understanding in which direction it should move.

To try to dig, you should put the excavator in the rear position and place it on special supports. After that, you can try to control the boom and work with the soil.

Please note that excavators can radically differ from each other, both in power and in the control system. If you want to learn how to work efficiently with such machines, then it is advisable to take special courses where you can gain experience. Only Full time job with an excavator will allow you to feel it correctly and perform the most difficult tasks.

Wheel excavators modern models can be equipped different systems management, but the requirements for them are the same, namely, management should be convenient and easy.

The driver must operate the excavator without much effort, since in just one hour of work he sometimes has to make up to 4000 inclusions of working mechanisms. Accordingly, this number increases several times over the shift.

Wheel excavator control system requirements

From any equipment used on construction sites, production or in a quarry, high labor productivity is required. The same requirements apply to the work of an excavator. Control wheeled excavator carried out by the driver, on the speed of which depends on the productivity of work.

Therefore, from the control system of excavators, which are produced by various enterprises and firms, the consumer expects certain qualities:

1. The effort required to press the levers and pedals should not be large.

2. The inclusion of mechanisms should occur smoothly.

3. The transfer of energy from control to mechanisms must be instantaneous.

4. Regulation is required simple but reliable.

5. Ability to work without failures at temperatures from -50O to +50O.

6. Using the maximum of automation.

Each control system taken separately can only partially fulfill all these requirements.

How to drive a wheeled tractor

Ways to transfer energy to the mechanisms of the excavator:

Lever. Mechanical servo mechanisms may be used. The simplicity of design and the possibility of smooth switching with high sensitivity are the advantages of this method. Operation is complicated due to the presence of a large number of levers, rods and hinges. Management requires a lot of physical strength from the driver.
Pneumatic. Gas (air) pressure is used. Smooth start, the ability to work with the engine off, simple blocking of individual mechanisms - all these qualities are among the advantages of this method.
Hydraulic. The mechanical force of the liquid (oil) is used. Advantages: compactness and lack of levers with a complex design, requires little effort to operate. Disadvantages: dynamic loads on mechanisms due to sudden switching on.
Combined. A combination of several methods in one system.

The complete set of a certain control system depends on the power of the excavator, the type of drive, the required reliability of actions. Large capacity bucket requires a lot of effort on the control lever, so manual mechanical control won't fit. It is used in wheeled excavators with a bucket up to 0.4 mg with a single-engine drive.

Operation of the hydraulic control system

This system has been extensively improved in last years, has found the widest application to the design of excavators, the mechanisms of which are driven by a single engine.

The design of the control system based on hydraulics has the main instruments and components:

Pump. Works for high pressure. Provides in hydraulic system fluid movement. Powered by an excavator engine.
An accumulator with a filter that plays a role in starting the engine of a temporary pressure tank.
Distribution and return manifolds, control spools.
Hydraulic cylinders that are on the mechanisms. Designed to turn mechanisms on and off.

Pipeline and fittings

Sometimes in design hydraulic control pump not included. In this case, the force on the lever is slightly reduced, but the system itself has smaller parts and assemblies due to fluid pressure and does not have a complex system of levers.

The hydraulic system without the use of a pump is used on low-power excavators and separately for brake system other models.

Control systems with a pump and hydraulics completely facilitate the work of an excavator who only moves the spools. The force is created by a pump, the liquid under pressure enters the cylinder mounted on the mechanism.

Operation of the pneumatic control system

It is used on excavators with different bucket sizes. The system uses normal air. The pressure does not exceed 10 kg/cm2, so cylinders are used large sizes and significant weight, which refers to the disadvantages pneumatic system management.

The main devices and components of the pneumatic system design:

Compressor forcing air into the system.
Oil and water separator.
Receiver.
Pressure regulator.

Coming from the compressor compressed air into the oil sump, then through check valve through the pipeline enters the tanks. On the way to the working cylinders, the compressed air is freed from moisture in the condensate collector, and is regulated in the electro-pneumatic distributor.

The spools can be controlled manually or electromagnetically.