Overview of the parameters of dump trucks Kraz-256, 257
The KrAZ-256, KrAZ-256B, KrAZ-257 and KrAZ-258 vehicles were created on the basis of the previously produced KrAZ-222B, KrAZ-219B and KrAZ-221B vehicles.
KrAZ-256, 256B, 257, 258 vehicles have higher economic and technical indicators, since they have a more powerful and economical engine, which allowed to increase the productivity of cars, increase movement speed, improve throttle response and significantly reduce fuel consumption.
KrAZ-256 and KrAZ-256B dump trucks are designed for various quarry and construction works together with excavators, the bucket capacity of which does not exceed 3 m3.
The platform of KrAZ-256, 256B vehicles is tilted back by a two-cylinder hydraulic mechanism.
KrAZ-257 car general purpose designed for mass transportation of various cargoes.
The KrAZ-258 tractor truck is designed for towing heavy semi-trailers.
The KrAZ-258 tractor vehicle is equipped with a semi-automatic fifth wheel coupling device that provides quick hitch and uncoupling it from the semi-trailer.
Technical characteristics of KrAZ-256 / KrAZ-257 vehicles
Carrying capacity, t. - 10/12
The largest total weight of the loaded trailer or semi-trailer, t. - 10 / -
Control fuel consumption per 100 km, l. - 16.6
Maximum speed, km/h - 62/70
The greatest rise overcome by the car on a dry road, hail. - 45/36
The braking distance of a car with a full load from a speed of 40 km / h to a complete stop, m. - 18/18
The smallest turning radius, m. On the track of the front outer wheel - 20/20
The smallest turning radius, m. On the wing of this wheel - 10.5 / 12.5
Front wheel track, mm - 1950
Track rear wheels, mm - 1920
Ground clearance, mm. under the front axle - 290
Ground clearance, mm under the crankcases of driving axles - 290
Overhang angles (under load), deg. front - 42
Overhang angles (under load), deg. rear - 55/18
Length, mm - 8100/9660
Width, mm - 2640/2650
Height, mm - 2792/2620
Distance from the front axle to the axle of the rear bogie, mm - 4780/5750
Rear bogie base, mm - 1400/1400
Curb weight of the vehicle, kg - 11500/11130
Distribution own weight on the front axle, kg - 3930/4300
Distribution of own weight on the rear bogie, kg - 7570/6830
Gross vehicle weight, kg - 21575/23355
Engine KRAZ-256, 257
Engine type - Four-stroke diesel YaMZ-238
Number of cylinders - 8
The arrangement of the cylinders is V-shaped, with a camber angle of 90 °
Cylinder firing order - 1-5-4- 2-6-3-7-8
Cylinder diameter, mm - 130
Piston stroke, mm - 140
The working volume of cylinders, l - 14.86
Compression ratio - 16.5
Maximum power, l. With. - 240
Speed crankshaft at maximum power, rpm - 2100
Maximum torque, kgm - 87
Transmission KrAZ-256, KrAZ-257
Clutch KrAZ-256, KrAZ-257 - Double-disk, dry, with peripheral pressure springs.
Gearbox YaMZ-238K or YaMZ-236S - Mechanical, five-speed with synchronizers in second, third, fourth and fifth gears.
Transfer box KrAZ-256, KrAZ-257 - Mechanical, consists of a two-stage additional box And transfer box With center differential in the drive to the rear axles.
On the KrAZ-256 dump truck, from the transfer case, through the power take-off, the oil pump of the platform lifting mechanism is actuated.
Cardan drive KrAZ-256, KrAZ-257 - Open, with tubular cardan shafts, whose cardan shafts are equipped with needle bearings.
An intermediate support is installed in the drive line of the rear axle KrAZ-256, KrAZ-257.
Drive axles KrAZ-256, KrAZ-257 - Double main gears with bevel gears with spiral teeth and spur gears with straight teeth.
The gear ratio of the main gears is 8.21.
The differential is conical with four satellites.
The axle shafts are completely unloaded. Beams of bridges KrAZ-256, KrAZ-257 are made of cast steel.
Chassis KrAZ-256, KrAZ-257
Frame KrAZ-256, KrAZ-257 - Riveted. Longitudinal beams from channel No. 30. Stamped crossbars.
The front buffer is fixed at the ends of the frame longitudinal beams with brackets.
Towing device - Double-acting with locking lock. front towing hooks welded to the longitudinal beams of the frame.
Front axle - I-section. Steering trapezoid located at the rear
Front suspension KrAZ-256, KrAZ-257 - On two longitudinal semi-elliptical springs with two telescopic hydraulic shock absorbers.
The ends of the springs are fixed in rubber cushions.
Rear suspension KrAZ-256, KrAZ-257 - Balancing type, on two longitudinal semi-elliptical springs.
Pushing forces and reaction moments are transmitted by a system of six reaction rods.
Steering and brakes KrAZ-256, KrAZ-257
Steering gear KrAZ-256, KrAZ-257 - Worm with side sector, gear ratio 21,5.
Power steering KrAZ-256, KrAZ-257 - Pneumatic.
Foot brake - Shoe (on all wheels), pneumatic brake drive.
Hand brake (parking) - Shoe type with a mechanical drive.
Special equipment KrAZ-256, KrAZ-257
Power take-off box of KrAZ-256 and KrAZ-256B vehicles - Mechanical, single-stage, gear ratio 1.
Platform lifting mechanism - Hydraulic, acts on the platform through a lever-balance system.
limiter maximum angle platform lifting - Three-way, made in the same housing with the pump.
The pump of the lifting mechanism - Double-hinged, with an automatic lock.
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- Maintenance of the fuel system of the D-245 diesel engine
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- Assembly operations for the basic components of the ZIL-130 engine
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| YaMZ-238 | |
|---|---|
| Manufacturer | Yaroslavl Motor Plant |
| brand | YaMZ-238 |
| Volume | 14 866 cm 3 |
| Max power | 240 l. With. (176 kW), at 2100 rpm |
| Max Torque | 883 Nm, at 1500 rpm |
| Configuration | |
| cylinders | 8 |
| Acceleration to 100 km/h | 0-60 km/h 32 sec |
| Combined fuel consumption | 38 l/100 km |
| Cylinder diameter | 130 mm |
| piston stroke | 140 mm |
| Compression ratio | 16,5 |
| The order of operation of the cylinders | 1-5-4-2-6-3-7-8 |
| mechanical 5-speed | |
|---|---|
| Manufacturer | YaMZ |
| Model | 236N |
| Type | mechanical |
| Number of steps | 5 |
| gear ratios | |
| 1 gear | 5,26 |
| 2 gear | 2,90 |
| 3rd gear | 1,52 |
| 4th gear | 1,00 |
| 5th gear | 0,66 |
| Reverse gear | 5,48 |
| Switching | floor lever |
In 1974, the KrAZ-256B1 dump truck was awarded the State Quality Mark of the USSR.
In the mid-1970s, the KrAZ-256Bs produced were equipped with a new two-wire brake system.
By the beginning of 1975, the electrical equipment of the KrAZ-256B was unified with the electrical equipment of other trucks produced in the USSR by 71% (out of 55 products and devices, 39 were unified, and 16 were used only on the KrAZ-256B), and it was decided to increase the level of unification to 75% (due to the unification of switches and fuses KrAZ-256B with those used in MAZ trucks and the installation of a new standardized model sound signal) .
As a result of improving the design, over time, the resource of the KrAZ-256B produced increased: if before 1970 the resource of the KrAZ-256B was 100 thousand km, then for those produced in 1970 - 1976 - 150 thousand km, and for those produced in 1977 - 1982 years - 160 thousand km. By 1985, the resource of serial KrAZ-256B1 was increased to 165 thousand km.
In 1983, specialists from the NAMI Central Research Polygon and the Kremenchug Automobile Plant conducted experimental studies to reduce the metal consumption of the KrAZ-256B1 units, as a result of which, by the end of 1984, the design of the manufactured KrAZ-256B1 was changed - a subframe from a bent profile was introduced, which reduced the weight frames for 115 kg. In addition, in 1984, a version of the KrAZ-256B1 with a lightweight body was developed (the weight of which was reduced by 100 kg), designed to transport goods with a density of less than 2 t / m³. Body structure calculations were performed using a computer.
Average resource of KrAZ-256B and KrAZ-256B1 dump trucks up to the first overhaul was 165 thousand km, after which the overhaul provided an additional 132 thousand km between repairs.
Mass production KrAZ-256 was discontinued at the end of 1993, the last KrAZ-256B1S was manufactured in January 1994.
In October 2008, the Ministry of Construction of Cuba and HC "AvtoKrAZ" created joint venture for the repair and modernization of KrAZ trucks (at that time there were several thousand KrAZ trucks in Cuba, mostly worn-out and requiring repair of KrAZ-256B dump trucks). In January 2009, a Ukrainian-Cuban joint venture KrAZ-SOMEC was opened in the city of Cienfuegos, the capacity of which allows upgrading up to 200 KrAZ vehicles per year, in total, more than 300 KrAZ vehicles were modernized by the enterprise until August 28, 2014.
Design Description
The car received a five-speed mechanical box gears, transfer case - two-stage, with center differential lock.
Cabin - triple, with a wooden frame and metal sheathing, without bed located behind the engine; driver's seat - sprung, adjustable for driver's weight, length, height and backrest.
Disk wheels, tires - pneumatic, chambered (tire size - 12.00R20 (320R508)).
The body is a metal bucket type with rear unloading (4440 x 2430 mm), the unloading mechanism is hydraulic, two-cylinder, acts on the platform through a lever-balancing system. Pump - gear, mod. KrAZ-222B; operating pressure 34 kgf / cm 2. The volume of the hydraulic system is 70 liters.
Suspension - front, on two semi-elliptical springs with shock absorbers, the ends of the springs are installed in rubber support pads. Rear - balancing on two semi-elliptical springs with six jet rods, the ends of the springs are sliding.
Brakes:
Service brake system - with drum mechanisms (diameter 440 mm, front lining width brake mechanisms- 90, rear - 140 mm, spreader - cam using brake cylinders double-circuit pneumatic drive (one circuit for the front and middle bridges, the second - on rear axle). Parking brake - transmission, drum, with inner and outer pads and mechanical drive. Mounted on the output shaft of the transfer case and acts on the rear axle.
Additional equipment: pre-heater of the engine, double-acting towing device with locking lock.
Variants and modifications
Over the years of production, KrAZ-256 slightly changed its appearance. In particular, dump trucks produced in 1966-1969 differed in the location of the headlights, on brackets mounted on the wings, closer to the hood and separate direction indicators, as well as the presence of a protective grille in front of the headlights. Since 1969, the headlights and direction indicators have been moved to special boxes mounted on the wings. Since the late 80s, the production of cars with a simplified headlight arrangement began, which were now again separated from the direction indicators and located above the bumper, and the direction indicators themselves were installed under them in the bumper. In addition, some cars left the assembly line not with disk, but with diskless front wheels of the MAZ-500 type.
Specifications
KrAZ-256B in the cinema
- Track (1978)
In the gaming and souvenir industry
The scale model of the KrAZ-256B car is produced by Studio KAN (Krasnodar), Kimmeria (Kherson), Damir (Kazan), Start Scale Models (China), Autohistory (China), Nash Avtoprom (LLC Feran ", Russia / "ARUM Limited", China).
Notes
- KrAZ vehicles // magazine " Automotive industry", No. 8, 1984. pp. 30-31
- N. Chistov. Modernized KrAZ // "Behind the wheel", No. 10, October 1961. p.14
- A. I. Goryainov. M. F. Lavrinovich. Springs of friendship and brotherhood: Minsk - Kremenchug. Kharkov, "Prapor", 1986. pp. 30-36
- Kremenchug automobile plant named after 50th Anniversary of Soviet Ukraine // Journal "Automotive Industry", No. 8, 1984. pp. 29-30
- Transport of the USSR. Results for fifty years and development prospects. M., "Transport", 1967. p.207
- V. V. Tabolin. KrAZ vehicles. Efficiency, reliability, quality // Automotive industry magazine, No. 12, 1982. pp. 14-16
- I. G. Barannik, A. A. Zdanovsky, N. S. Kononchuk. Unification of electrical equipment of trucks // magazine "Automotive Industry", No. 1, 1975. pp. 4-5
A series of KrAZ trucks is considered one of the best in the history of machine-building production in the USSR. For almost fifty years of existence, several tens of thousands of all-terrain vehicles with various configurations And technical specifications. popular model is KRAZ 256, which was exported to forty countries of the world and was distinguished by an innovative approach of engineers to the development of many mechanisms. Let's take a closer look at all aspects of the Soviet all-terrain vehicle.
So, the idea of creating a new dump truck arose at the Kremenchug plant in the early 60s. More early model KrAZ-222 "Dnepr" at that time was very outdated and lost its attractiveness in the eyes of the public. It took the engineers about two years to develop the truck, during which they were not only able to come up with some revolutionary mechanisms, but also learn from the experience of colleagues from other republics. For example, experts from the Minsk Plant took part in the assembly of the KRAZ 256 car, offering an original design of the main chassis.
Truck assembly line production started in 1967
The new Soviet unit almost immediately received recognition from the leadership of the USSR, and soon even a second-class award from VDNKh. The release of the car became a new stage in the development of the Kremenchug plant, which stopped the production of many outdated models, including the KrAZ-222 and YaAZ-210E. In the mid-70s, KRAZ 260 B1 was awarded state sign quality of the USSR, which is still considered one of best performance power and productivity.
In 1975, trucks were equipped with a unique electrical equipment, manufactured specifically for the KRAZ 256B models. In parallel, the Kremenchug plant began to switch to a higher quality and ecological production, reducing the use of low-alloy materials by up to twenty-five percent. Each new dump truck model had elevated level speed, motor power and other improved technical characteristics. For example, a car in 1970 could reach speeds of up to one hundred kilometers per hour, and already in 1977 more than one hundred and fifty kilometers.
Mass production of the legendary series ended after the collapse of the USSR in 1993 due to lack of parts and lack of proper funding. last car KRAZ was released in 1994 specifically for enterprises in the Northern regions of Russia.
KRAZ 256 modifications
Since in the period from the 70s to the 90s the Soviet leadership invested a lot of money in the development heavy equipment, KRAZ 256 was produced in huge quantities and various variations. It is almost impossible to count how many cars were produced, since only one KRAZ-256B1S model has almost twelve thousand copies.
The KRAZ series has the following modification options:
- The first KRAZ 256 dump truck was produced in 1960 and was equipped with power plant with a power of 215 hp
- The second product of the plant is a twelve-ton KrAZ-256B unit, whose power is 240 hp. Even today, such indicators speak of high degree productivity.
- At the end of the 60s, engineers presented a unique KrAZ-E256BS model designed to work in the harsh conditions of the northern regions of the country. After some successful tests, it was decided to put the "snowmobile" into mass production.
- KRAZ-256BS was also developed for the needs of hard-to-reach regions of the USSR, where cars with increased resistance to cold and indicators of patency.
- KrAZ-256B1 was an ordinary twelve ton dump truck with separate brake actuators.
Interesting fact: in 2008, the leadership of Cuba began negotiations with Ukraine on the creation of a special joint project for the repair and modification of the KRAZ 256 dump truck. Today, there are about three thousand trucks in Cuba that need repair and can be used in the future for government orders. In 2014, the Cuban company KRAZ-SOMEC, together with the Kremenchug plant, modernized about three hundred all-terrain vehicles.
Some KRAZ 256 models were developed specifically for operation in the Far North
In addition to the main car models, was created special unit KRAZ-256B1-OZO for the removal of radioactive waste from the Chernobyl zone. The purpose of the dump truck speaks for itself, so it is equipped with a maximum degree of protection against radiation, durable glass and has increased load capacity. In total, about twenty such machines were produced, which today have not been used for a long time and in most cases have been disposed of.
Appearance
Depending on the year of manufacture, KRAZ 256 has a different appearance. Until the end of the 60s, the dump truck was produced according to outdated drawings of its predecessors, and only in 1969 received an updated design with a new headlight arrangement and wheel coverage. You can follow the evolution of the external structure in the photos and videos below.
The driver's cabin is located behind the main power plant and can accommodate up to three passengers, including the operator. A well-designed chair takes into account all the parameters of a person and is adjustable depending on the height, weight and backrest. Thanks to a well-thought-out design, KRAZ 256 perfectly maneuvers on the roads, moves smoothly under any conditions and off-road.
The truck is equipped with five step box gears, and the fifth speed of the gearbox is responsible for the increase. In turn, the brake system regulates the uniform distribution of the load and protects against skidding on steep descents. The diameter of the drum device is four hundred and forty millimeters, and also has a special mechanical drive.
It is worth noting that braking system dump truck has certain disadvantages and was often criticized by Soviet engineers. At long journeys in mountainous terrain or vertical slopes, operators could not use the engine brake function, as this would disrupt the operation of the compressor. For this reason, it was extremely difficult to stop the car on the move, and very often such situations led to serious accidents.
KRAZ 256 was supplied to forty countries around the world
Specifications
The total length of the truck is almost 8200 mm, the height is 2600 and the width is 2640. Important: KRAZ 256 can be equipped with a special visor, which increases its height by one hundred and ninety millimeters. The ground clearance of the dump truck is 290 mm, and wheelbase just over four thousand. The parameters of the front and rear track practically do not differ from each other, equaling 1950 and 1920 mm.
Considering the carrying capacity of KRAZ, it should be noted that total weight equipment of the car is approximately twelve tons. With such an indicator full mass the entire dump truck is doubled and equals twenty-four and a half tons. load capacity latest models machine does not exceed 12,000 kg, and the entire main load, as a rule, falls on rear axles carts. At the same time, despite such impressive dimensions, KRAZ 256 accelerates to 68 km / h when fully loaded, and the lighter the equipment, the higher the speed indicator.
The all-terrain vehicle is equipped with a powerful eight-cylinder power diesel plant from Yaroslavl plant, whose power is 240 hp, and the working volume is almost fifteen liters. At correct operation the car consumes thirty-eight liters of fuel every hundred kilometers, and the rotational speed is 2100 revolutions per minute. It is worth noting the volume fuel tank 330 liters, thanks to which KRAZ 256 can be on the road for a long time without additional refueling.
To protect the engine from freezing, a special pre-heater is installed on the truck, which is responsible for the operation of the engine in winter time. If you believe the numerous customer reviews, then start KRAZ 256 at a low sub-zero temperature will not be difficult, and some models are even designed for operation in the Far North.
A popular analogue of KRAZ is german car Magirus-Deutz 232D19
Price
Buy new model car KRAZ 256 today is impossible, since it was discontinued almost twenty-five years ago. But the truck is in due demand even in 2019, so buying it on secondary market will also require some effort from you. The average cost of a dump truck in good condition equals 150-200 thousand rubles, depending on the year of issue. It will also not work to take a truck for temporary use, since not a single large company providing rental services has a Soviet all-terrain vehicle available.
Interesting fact: In 2009, in the city of Cienfuegos, Cuban designers assembled a modernized KrAZ-256BM1, based on the popular Soviet model 256.
Summing up, it should be noted that, despite the huge number of analogues, KRAZ 256 is still considered one of the best cars of his time and received many honorary awards. Buying a truck in good condition will not be easy, but it is quite possible. Additionally, for a dump truck, you can buy a lot of parts and special installations both from the Kremenchug plant and from others modern companies, thanks to which the unit will work much more efficiently and will not require quick repairs.
Article published on 07/29/2015 05:34 Last edited on 07/29/2015 05:48
KrAZ-256B is a heavy dumper, produced from 1965 to 1977 at Kremenchug car factory. It had a 6x4 wheel formula and, from a technical point of view, was a continuation of the development of the design of the KrAZ-222 dump truck, which also had the second name "Dnepr".
On its basis, in addition, the KrAZ-256B1 truck was created, which differs from the basic prototype in the presence of some minor changes in the design, as well as the use of a divorced drive in it. brake system. It was mainly operated in quarries, as well as on roads of the first and second categories, which could withstand axial load up to ten tons.
The creators of this truck equipped it with a five-speed manual transmission, a two-stage transfer case with a lockable center interval.
The cabin here was three-seater and it was located directly behind the engine, and was also equipped with a sprung driver's seat, adjustable in length, weight, height, etc.
A bucket-type body was installed on the car, which was unloaded back using a two-cylinder hydraulic drive system, which influenced cargo platform using a lever-balancing system.
KrAZ-256B was armed with a front suspension on two semi-elliptical springs and shock absorbers. The rear one had a balancing design on a pair of semi-elliptical springs.
The brake system of the truck consisted of drum mechanisms, parking brake was transmission type, mechanically driven. It was mounted on the transfer case shaft and acted directly on the rear axle.
From additional equipment it is worth noting preheater power unit.
As for modifications, modernization this car passed several times. So, in particular, in 1966-1969, the location of the headlights on the truck changed, for example, they were installed on brackets mounted on the wings, as well as in other ways. In addition, the protective grille mounted in front of the headlights also changed.
In 1969, the headlights, together with the direction indicators, were moved to special boxes. They were also installed on the wings. Later, in the 80s of the last century, the Kremenchug plant mastered the production of cars on which headlights were installed in a simplified way. Now they were again separated from the “turn signals” and were now placed above the bumper. Also, some cars were armed with diskless front wheels from the MAZ-500.
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Technical characteristics of KrAZ-256B:
| Total information | |
| Manufacturer | KrAZ |
| Production years | 1965-1995 |
| Design | |
| Platform | dump truck |
| Layout | front-engine, rear-wheel drive |
| Wheel formula | 6-4 |
| Engines | YaMZ-238 |
| Transmission | mechanical 5-speed |
| Transfer case | two-stage. |
| gear ratios | 1st gear - 2.28; 2nd gear - 1.23. G |
| main transmission of driving axles | double, gear ratio - 8.21. |
| Mass-dimensional | |
| Length | 8190 mm |
| Width | 2640 mm |
| Height | 2620 (with canopy 2790) mm |
| Clearance | 290 mm |
| Wheelbase | 4080+1400 mm |
| Rear track | 1920 mm |
| Front track | 1950 mm |
| Weight | 12050 kg |
| Dynamic | |
| Max. speed | 62 km/h |
| On the market | |
| Successor | KrAZ-6510 |
| Related | KrAZ-255B, KrAZ-257 |
| Other | |
| load capacity | 12000 kg |
| Fuel consumption | 38 l/100 km. |
| Volume of the tank | 330 l. |
Tipping mechanism of the KrAZ-256b vehicle
The KrAZ-256B vehicle is equipped with a hydraulic two-cylinder tipping mechanism acting on the body through a lever-balancing system. Main constituent parts its are: power cylinders, swinging on a common axis; oil pump driven by a cardan shaft from the power take-off; linkage and subframe.
The lever mechanism consists of a balancer and levers (shoulders). The cylinder rods are pivotally connected to the balancer by means of two pins and brackets. The balancer is pivotally attached to the base of the body by means of levers. Limiters are provided on the balancer, which do not allow the body to go through the limit angle of elevation.
The tipping mechanism is controlled from the driver's cab using two levers. One of them is the control valve switch lever oil pump, the second - a lever for turning on the power take-off.
The lever of the oil pump control valve can occupy three positions: “Neutral” (lever in the rear position), “Raise” (lever in the middle position), “Lower” (lever in the forward position). Transport position lever - "Neutral".
The scheme of operation of the overturning mechanism is shown in fig. 64. To lift the body, you must first turn on the Power take-off as described in the "Power take-off" section. Then move the oil pump control valve switch lever to the "Lift" position. In this case, the control valve will take position II (Fig. 64, b), and the oil will be pumped through the oil pump through check valve will be supplied from the right cavity (see Fig. 64, c) of the power cylinders to the left. The piston under the influence of oil will begin to move and through the rod act on the lever-balance system of the tipping mechanism. The body will rise.
Rice. 63. Power take-off;
1 - breather; 2 - cover front bearing driven gear shaft; 3 - bearing; 4 - driven gear; 5 - the axis of the intermediate gear; 6 - intermediate gear bearing; 7 - intermediate gear; 8 - installation wiit of the axis; 9 - screw lock washer; 10 - cover Rear bearing driven gear shaft; 11 - stuffing box; 12 - fork cardan shaft winch drive; 13 - crankcase; 14 - plug of the stem socket; 15 - ball-clamp of the fork rod; 16 - plug stem; 17 - power take-off fork; 18 - cover; 19 - sealant.
Rice. 64. Scheme of operation of the tipping mechanism:
a - diagram of the distribution of oil in the cylinders; b - switching diagram of the pump control valve for various positions of the dump truck body; c - diagram of the operation of the mechanism at the time of the beginning of the lifting of the body; d - diagram of the operation of the mechanism at the beginning of lowering the body (the arrows show the direction of the oil flow); I - "Neutral position"; II - "Rise"; III- "Lowering"; 1 - oil pump; 2 - pump control valve; 3 - distribution head; 4 - power cylinders; 5 - balancer; 6 - body floor.
To lower the body, the control valve shift lever is set to the "Lower" position. In this case, the control valve will take position (Fig. 64, b).
If it is necessary to stop the body in an intermediate position when lifting or lowering, the oil pump control valve switch lever must be set to the “Neutral” position.
As working fluid mineral oil is used in the hydraulic system of the hoist. The oil must
be clean, without mechanical impurities. The viscosity of the oil must correspond to the temperature conditions of the mechanism. With excessively viscous oil, the pump operates with high stress and shock, which can cause damage to parts of the pump or its drive. If the viscosity of the oil is insufficient, the pump does not generate required pressure in power cylinders due to increased leakage through internal clearances in the pump and cylinders.
When dump trucks leave the factory, the tipping mechanism cylinders are refueled for summer operation (at temperatures above +5 °C) industrial oil 20 (spindle. 3) GOST 1707-51, for work in winter (at temperatures below +5 ° C) - spindle oil AU GOST 1642-50.
With absence specified oils substitutes are allowed: in summer - oil with kinematic viscosity 18.6-47.8; in winter - oil with a kinematic viscosity of 4.1-13.6 cst.
Tipping mechanism care
Care of the tipping mechanism consists in periodic external examination it, tightening the fasteners, thoroughly lubricating the rubbing surfaces, tightening the stuffing box seals and (if necessary) adding oil to the cylinders.
During operation of the tipping mechanism, the oil is gradually consumed due to leakage, so it is necessary to periodically add it to the cylinders.
Oil is poured into the power cylinders through the oil filling holes in the rear upper part of the cylinder. The oil filler plug is double, the smaller plug is the control plug.
Topping up or changing the oil in the cylinders must be done in a certain sequence.
To add oil to the cylinders, you must:
2. Put additional supports under the body, providing complete security works.
In the absence of securely installed props, it is strictly forbidden to perform any work under the body.
3. Set the oil pump control valve switch lever to the "Lower" position.
4. Thoroughly clean the oil filler plugs and the surface around them from dust and dirt; unscrew the oil filler plugs on the cylinders.
5. Fill oil alternately into both cylinders (the oil level should be at a distance of 1-2 cm from the edges of the oil filling holes); oil should be poured slowly (especially at low temperatures or high oil viscosity), always through a clean funnel with a mesh.
6. Screw the plugs of the oil filling holes into the cylinders, having previously unscrewed the control plugs from them.
7. Remove additional props.
8. Raise the body and lower the stop stand.
9. Slowly lower the body ( excess oil from the cylinders will pour out through the holes for the control plugs).
10. Slowly raise the body, install the thrust stand and additional props, screw in the control plugs. Remove the supports and lower the body. Slowly raise the body 2-3 times to full lift angle. If the body does not raise to full angle, add oil again.
The first change of oil in the cylinders of the tipping mechanism should be carried out after the first 100-120 lifts. The next oil change should be carried out during seasonal maintenance.
For full shift oils, do the following:
1. Raise the body, install the stop stand.
2. Put additional props under the body.
3. Set the oil pump control valve switch lever to the forwardmost position "Lower".
4. Place clean dishes under the cylinders and unscrew the oil filler and drain holes cylinders (after removing dust and dirt from them and the surrounding surface); when the oil drain slows down, turn it out air locks from the support cylinder heads; if it is necessary to drain the oil from the pump, unscrew the lower conical plug of the pump.
b. When the oil has completely drained, screw the conical plug into the pump housing and the plugs into the oil filler holes of the support cylinders.
6. Pour slowly fresh oil into the cylinders (through a funnel with a grid) until it appears from the air holes in the supporting cylinder heads.
7. Screw the air plugs into the support heads and then fill the cylinders with oil, as indicated in the rules for adding oil.
When topping up and changing oil, care must be taken to ensure that the oil being poured is clean and does not contain mechanical impurities.
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