The locking device designed to connect the hydraulic system of the KamAZ-55102 dump truck-tractor with the trailer hydraulic system consists of two cases 1 and 7, one of which is connected to the tractor's discharge line, the other to the trailer.

In the case of a dump truck with a trailer, both parts are interconnected by a nut 5.

At the same time, balls 3 and 4 of the shut-off valves are pressed against each other from the support belts and do not interfere with the flow of oil.

When working without a trailer, it is necessary to disconnect its line, for which it is enough to unscrew the nut.

In this case, the balls under the influence of springs will block the holes in the housings and prevent oil from flowing out of the hydraulic system

Closing device

Locking device: 1 - tractor locking device body, 2.6 - springs, 3.4 - balls, 5 - nut, 7 - trailer locking device body, 8 - trailer plug, 9 - tractor plug

Platform lifting hydraulic system operation

The hydraulic system of the platform lifting mechanism works as follows.

To turn on the power take-off, disengage the clutch and set switch 13 to the on position (in this case, the control lamp 14 lights up).

The current through the thermobimetallic fuse 16 is supplied to the electropneumatic valve 6 electromagnet winding, the core of which, moving, opens the valve.

Air from the pneumatic system enters the cavity of the pneumatic chamber 4 of the power take-off.

When the clutch is engaged, oil pump 2 starts working.

Oil from tank 1 through the suction and discharge cavities of the pump enters the control valve 7 through the pipeline, and then drains into the tank.

This oil circulation contributes to its heating in winter, which improves the working conditions of the hydraulic system of the lifting mechanism.

Scheme of the KamAZ-5511 dump truck platform lifting mechanism

Fig. 2 Scheme of the mechanism for lifting the platform of a KamAZ-5511 dump truck: 1 - oil tank, 2 - oil pump, 3 - power take-off, 4,8,9 - pneumatic chambers, 5 - hydraulic system safety valve, 6, 10, 11 - electropneumatic valves, 7 - control valve, 12 - switch for lifting 11 and lowering platform 1, 13 - power take-off switch, 14 - control lamp for turning on the power take-off, 15 - batteries, 16 - fuse, 17 - hydraulic cylinder, 18 - platform lift limit valve, 19 - filter relief valve, 20 - filter

To raise the platform of the KamAZ-5511 dump truck, switch 12 to position 11.

In this case, the current passes through the windings of the electropneumatic valves 10 and 11, the cores of which, moving, open the valves.

Air from the pneumatic system is supplied to pneumatic chambers 8 and 9 of control valve 7.

Oil from the control valve enters the hydraulic cylinder 17 through pipelines.

Under oil pressure, the hydraulic cylinder links are sequentially extended, raising the platform.

As the platform rises, the hydraulic cylinder tilts; when the maximum angle of inclination is reached, the hydraulic cylinder body is pressed on the adjusting screw of the valve 18 for limiting the platform lift and the oil is drained into the tank through the valve.

Platform lifting stops.

To stop the platform in an intermediate position, switch 12 to the neutral position.

At the same time, the electropneumatic valves 10 do not turn off, the air exits the working cavities of the pneumatic chambers 8 and 9 into the atmosphere, the hydraulic cylinder line closes, and the injection cavity of the control valve communicates with the drain line and the oil from the pump is drained through the control valve into the tank.

To lower the platform, switch 12 to position 1. The current passes through the winding of the electropneumatic valve 6, the core of which, moving, opens the valve.

Air from the pneumatic system enters the pneumatic chamber 8 of the control valve, and oil is drained from the hydraulic cylinder into the tank through the control valve.

When the platforms are lowered, it is necessary to set switch 13 to the off position (having previously disengaged the clutch). The oil pump stops working.

It should be noted that lowering the platform is possible both when the pump is running and when the oil pump is already turned off by switch 13.

The principle of lifting and lowering the platform of the KamAZ-55102 dump truck is similar to the operation of the mechanism for raising and lowering the KamAZ-5511 platform.

To raise the trailer platform after turning on the power take-off, turn on switch 19 in the cab of the KamAZ-55102 dump truck (when the tractor platform is raised, it must be turned off); the control lamp 18 will light up.

The current flows to the winding of the electromagnet, the core of which, moving

Further operations for raising and lowering the platform of the trailer are similar to the operations for raising and lowering the platform of the tractor.

After the trailer platform lifting mechanism is finished, turn off the switch 19, and the control lamp 18 will go out. It should be noted that only the tractor and trailer hydraulic cylinders can work alternately.

Scheme of the mechanism for lifting the platform of a KamAZ-55102 dump truck when operating as part of a road train

Scheme of the mechanism for lifting the platform of a KamAZ-55102 dump truck when operating as part of a road train: 1 - oil tank, 2 - pump, 3 - power take-off, 4, 9, 11, 12 - pneumatic chambers , 5 - hydraulic system safety valve, 6, 10, 13, 14 - electro-pneumatic valves, 7 - control valve, 8 - distributor, 15 - platform lifting and lowering switch 11 1, 16 - power take-off switch, 17 - control lamp for switching on the selection box power, 18—control lamp, 19—hydraulic distributor switch for tractor or trailer, 20—24 V current source, 21—locking device, 22—trailer hydraulic cylinder, 23—tractor hydraulic cylinder, 24—limiting valve, 25—safety valve filter, 26 - filter

Scheme of the Kamaz-5511 platform lifting mechanism

Another scheme for lifting the Kamaz 5511 platform

Scheme of the Kamaz-55102 platform lifting mechanism

Another scheme for lifting the Kamaz 55102 platform