What is a scraper, it is important for construction and utility workers to know. The machine is an earth moving vehicle. The main purpose is layer-by-layer cutting of the soil, its transportation and shipment to the appropriate storage sites. During operation, the unit compacts crumbling soil, which makes it possible to abandon highly specialized equipment.
Classification
Separation of the considered machines is made according to several parameters:
- By bucket capacity in cubic meters. High-capacity equipment includes modifications with a working body with a volume of more than 15 cubic meters. m.
- Load type. Here, the functioning systems of the main element are involved. The first type includes standard machines, the second - drag scrapers, as well as rotary and elevator variations.
- Unloading. In this segment, there are free, forced and combined models. In the first case, the procedure is carried out by releasing the bucket under its own weight. The second option involves pouring soil through the back wall, and in the third case, cleaningproduced by combining both of these methods.
- Drive type. It can be hydraulic, cable or electromechanical. Hydraulics includes a pump, a reservoir, connecting hoses and a distributor. In the cable version, work is carried out through a mechanical winch, special blocks and a system of polypastes. The operation of the electromechanical unit is based on the interaction of the motor, gear and gear device.
- Trailers, semi-trailers, self-propelled vehicles and wheeled trains.
Device
You can understand what a scraper is after studying the design features of the machine. A welded bucket equipped along the bottom edge with stepped special knives acts as a working body. The rear part is equipped with a buffer that plays a two-digit role. The specified element is intended to stop the bulldozer part of the equipment or move the tail of the rear wall in the desired direction. The side elements are made of steel sheets, which are reinforced with stiffeners.
There are several brackets and eyelets on the sides of this unit. These components are used to fix hydraulic cylinders and lever dampers. In addition, a support part for fastening the articulated harness and the rear wheel axle is provided. The rear part of the tipping is an active shield with guide rollers. They are not designed specifically to hold the back wall during work, but are focused on additional support. The main function in the indicated direction is performed by the shank and the system of hydraulic cylinders.
The front frame of the machine is made according to the type of arch and is equipped with a pivot, which aggregates with the tractor, levers, arch and draft joint. On the rope modification, the bucket is controlled somewhat differently. It is a single structure with the back of the equipment, consists of a pair of sidewalls and a bottom that smoothly transforms into a partition.
Working principle
The scraper shovel with forced unloading functions by turning the bottom with the back walls around its axis. As a result, the load spills out under its own weight as a result of the impact of the rear of the device. The hydraulic mechanism, which is equipped with advanced models, makes it possible to empty the bucket completely, with virtually no residue.
Trailed analogs are equipped with an earring that acts as a hitch when connecting the base to a tractor or tractor. The design also includes a pivot swivel mechanism, a carrier frame, a damper and a rear wall. Management is carried out through levers from the operator's cab. It should be noted that trailer modifications are relevant for operation in regions with variable terrain. Versions with a rope device work by means of forced unloading of the material. Self-propelled vehicles in this category include a regular tractor with one axle and a special semi-trailer.
Features
Scrapers on wheels with pneumatic drives and semi-trailer counterparts have pretty good speed performance. A machine with a single axle configuration is capable of accelerating up to 50-55 km / h, and with a dual axle - up to 70km/h A special train of 2-3 units makes it possible to significantly increase the performance of the units. An important element in improving performance is the use of a scraper conveyor, which is driven by an electric or hydraulic motor.
Functionality
Continuing to consider what a scraper is, it is necessary to pay attention to the high bucket loading parameter with a simultaneous decrease in traction, provided that the working body of the machine is filled by at least 25%. Automation of operation allows you to maintain the optimal mode of operation of the power plant, and also contributes to improved performance.
To improve the accuracy of work planning, in the case of maintenance of road cuts and embankments, the Stabiloplan automated system is used, which makes it possible to guarantee the stabilization of the longitudinal movement of the angular position of the bucket, which is especially important during planning work.
Technological nuances
In order to competently organize the work of a scraper for cleaning soil or snow, they first draw up a diagram of the operation of the machine. The performance of the unit is affected by the possibility of using the maximum capacity of the bucket. As practice shows, the most useful factor is manifested if the filling of the dump is carried out at a speed of 3-4 km/h.
At the same time, the thickness of the cut web does not exceed 70-350 mm. The final parameter depends on the specificationsoil and external operating conditions of the machine. If the equipment is equipped with a mechanism with a gradual deepening of the knife, the thickness of the cut and its width are automatically adjusted, depending on the power of the pusher and other subjective factors.
Operation
This method is well suited not only for cultivating the land, but also for snow scrapers. To reduce the time of work allows a stepped system of gaining a bucket. For example, the cutting of the surface is carried out by the method of ribbed-staggered setting, using successive rows of penetrations that are identical in length and placement. In this case, the processing width in one pass is no more than 1300 millimeters, the second row is carried out at a distance of half the parameter of the first finishing.
This approach makes it possible to increase the possibility of loading the blade by 12-15%, as well as reduce the time for collecting soil, snow or sand. It is noteworthy that in this way this machine can work without a tractor tractor. On loose soils, a special processing method known as "pecking" is used. In this option, the bucket is twice as deep, and the engine runs with a steady load. As a result, the vehicle runs intermittently until the blade is full.
Schematic
The diagram below shows a general design that allows you to understand what a scraper is.
- Bonnet part.
- Rope control.
- Cargo hold.
- Hydraulic traction.
- Work knife.
- Bottom.
- Connecting mechanism.
- Cuff.
- Wheel drive.
- Connecting mechanism.
- Device for starting the working unit.
- Additional hydraulic equipment.
As you can see, everything is quite simple.
