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Heavy cargo

KAMAZ BIG - HIM VIDEO

In Naberezhnye Chelny ready for serial production

20-ton dump truck KamAZ-6520.

Andrey SIDOROV

The larger the truck, tanker, plane, the cheaper the shipping. Therefore, giant vehicles are born. Dump trucks are no exception: if there was such an opportunity, sand would be transported to urban construction sites at BelAZ trucks. Only the asphalt is weak for them and the streets are cramped, because they are ordered on the federal roads. But the law of greatness is implacable - a big car is more profitable, and the carrier strives to buy just such.

The first KamAZ-5511 dump trucks were ten-ton. Then, after a small modernization (55111) - thirteen. The next, deeper processing of this model raised the carrying capacity to 15 tons (KamAZ-61115 - see ЗР, 2000, No. 3). It was impossible to build it further at the previous base - the design ran out of reserves. And the buyer demands, threatening to give preference to competitors.

Market research and consumer demands, as well as general trends in the automotive industry, have confirmed: in the coming years, demand for cars with a gross weight of 18–33 tons with an axial load of 10–13 tons will increase. In the KamAZ range, there were no such cars before.

The KamAZ-6520 dump truck became the base car of the new, heavy family. Created on the basis of original units, components and systems, as well as borrowed from current models, it is well adapted to the capabilities of existing production.

The KamAZ-740.51.320 engine - further modernization of the 260-horsepower 740.20–260. With the same cylinder diameter, the piston stroke is increased to 130 mm. Accordingly, the working volume and capacity increased. Now it is 320 liters. s., and the toxicity of the exhaust of the new engine moved into the next category and henceforth fits into more stringent Euro II standards.

The increased engine torque (125 kgf.m instead of the previous 80) entailed the installation of a more powerful clutch - a diaphragm double-disk with a driven disk diameter of 380 mm or a single-disk 420 mm.

For the same reason, the gearbox divider, which used to be in front of the gearbox on previous machines, gave way to the demultiplier placed behind it. Naturally, the switching scheme has also changed. Instead of the former flag controlling the "halves" - a double "H". The multiplier is activated by moving the gear lever in neutral. To the left - the first-fourth gears, to the right - the fifth-eighth.

The drive shafts of the new dump truck are equipped with splined flanges that unload the bolts from shear stress. Such a solution has long proved to be the best on foreign heavy trucks.

Driving bridges are brand new. To unload and reduce the size of the main gears are made spaced, with planetary wheel gears. Inter-axle and inter-wheel differentials are lockable - a supplement for dump trucks is very useful. These hard workers work in quarries, on sour primers and other inconveniences.

By the way, for main tractors based on this dump truck (yes, it is the dump truck that serves as the basis for a new family), single hypoid gearboxes are provided - you can’t conquer off-road with them.

The brake chambers from the "traumatic" places near the wheels moved up to the center of the bridge. There is no track to reach them.

The bridges of the rear bogie themselves are attached to the frame by jet rods with rubber hinges. The decision to replace the old ball fingers with them - a source of constant hassle on previous models - fully paid off. Immediately disappeared 12 points, requiring 600 grams of lubrication per month. The recommendation is to syringe them through two TO-2 - for asphalt. When working in dirt-filled tracks with such a frequency, it will fit right to change the hinges assembly.

Frame. As before - the staircase type, but its spars are channels of constant cross section. The increased load forced her to add strength.

Body. Its volume is increased to 12 mz. Traditionally durable and tough, he seems to be able to survive more than one car, while maintaining its original appearance and integrity. The proposal to reduce the thickness of metal sheets for the sake of relief was rejected at the design stage, recognizing the inappropriate saving - the body of a Russian car must withstand the impact of the excavator bucket. Such is the specificity of the work.

The hydraulic cylinder for lifting the body is still there, under the visor of the front side, but of a larger diameter, to match the carrying capacity. And what was pleasantly surprised, on both KamAZ trucks, which I had a chance to ride on, there were not the slightest signs of oil leakage. And on the speedometers of 35 thousand - there is hope that they will not flow at all.

Behind the wheel. I climb into an unusually high-standing cab (the tires of a dump truck with dimensions of 320x508 forced me to add a second step), I get a job in the driver’s seat and immediately notice several innovations in the driver’s workplace.

Gear shift lever of a different configuration. The parking brake valve is located on the front panel. Having "stumbled" out of habit several times on an empty place near the seat, the hand quickly remembers the new route and is no longer mistaken. The steering column allows you to change the angle. Otherwise, with the exception of a few little things, everything is in the same places.

For those seven minutes that an old excavator carefully piled rubble into the body, I manage to get quite comfortable driving, and we are going to work - to fill the road.

The impression of the first meters is a very light steering wheel. A loaded machine, even at low speed on the primer, is driven completely stress-free. There is no need to gas, increasing the pressure of the hydraulic booster pump: both the steering gear and the power steering pump are other, more powerful and productive.

320 l engine with. accelerates a loaded car quite briskly. The power-to-weight ratio remained almost at the level of 15-tonne (9.7 versus 10.6 hp / t), but the pile of rubble delivered by the heavy truck looks much more impressive. And the driver’s labor costs for its delivery are the same.

The reviews of gas workers, major customers and investors in the production of the new car are initially skeptical - where, they say, are he and Tatra and Mercedes-Aktros! - soon changed to positive. With the same, or even greater than that of the "foreigners", productivity, ours also have other advantages. Significantly cheaper (the estimated price of KamAZ is less than 60 thousand dollars), simpler, unpretentious. Unlike the Tatras, with their "parting" rear wheels, they break up the road much less. For asphalt, this may not matter, but for crushed stone roads at gas production it is very important not to drive a grader on them daily.

The skeptic will object - but reliability, comfort? In terms of comfort, perhaps, will be right. The noisy, shaky KamAZ still falls short of the European level. One word - "Spartan." As for the resource, it was determined by plant specialists to be 600 thousand km, which is quite acceptable for dump trucks by world standards.

But no matter how many praises KamAZ sang, the buyer himself will decide which dump truck to choose. As for tanks that are not afraid of dirt, it is much more important that the armor be strong.

Photo by Andrey SIDOROV

KamAZ-6520

General data: curb weight - 12 950 kg; the mass of the transported cargo - 20, 000 kg; Gross Vehicle Weight - 33, 100 kg; maximum speed - 90 km / h; angle of climb to overcome - not less than 30%; body volume - 12 mz; body lifting angle - 60 °; unloading direction - back. Engine: KamAZ-740.51-320, V8, compliance with toxicity standards - Euro II; power - 235 kW / 320 l. with.; maximum torque - 1225 N.m / 125 kgf.m. Tire Size: 12.00R20; wheels are disk.

1. A silica gel cartridge is used to drain the compressed air.

2. If necessary, the underrun support can be raised, for example, to support the rear wheels in the curb when loading concrete.

3. The new spare winch is much more convenient.

4. Instead of the front splitter on the new dump truck - a demultiplier.