SU1743941A1 - Hydraulic drive of dump truck tipping mechanism - Google Patents

Abstract

Usage: hydraulic actuators of self-unloading vehicles, in particular, hydraulic actuators of the tilting mechanism of the cargo platform of dump trucks of especially heavy-duty trucks. SUMMARY OF THE INVENTION: The piston cavity 17 of the hydraulic cylinders 15 is connected by an additional line with a slip into the hydraulic tank 18 through an overflow valve 8, which eliminates the possibility of spontaneous lifting of the loading platform due to clogged drainage and leakage of the working fluid into the rodless cavity of the hydraulic cylinder. 1 il.

Description

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The invention relates to hydraulic actuators for self-unloading vehicles, in particular, to the hydraulic lines of the tilting mechanism of the loading platform of especially heavy-duty dump trucks.

A combined hydraulic actuator of the tilting mechanism and power steering is known, which contains hydraulic cylinders of the tilting mechanism, power steering, two pumps communicated through a switchgear controlled by an auxiliary distributor, with piston and rod cavities of the hydraulic tilting mechanism and power steering management

The disadvantages of this hydraulic drive are the complexity of the design, the overestimated overall dimensions and the weight of the apparatus.

Also known is the hydraulic actuator of the tipping mechanism of a dumping vehicle, which contains two hydraulic pumps, double-acting tipping cylinders, a switchgear, a safety device containing a platform lowering valve, an electromagnetic-controlled bypass valve from the transmission control system.

This hydraulic drive scheme allows to reduce the metal consumption, power consumption and improve the usability of the vehicle.

The disadvantages of this scheme are low reliability and insufficient safety of the vehicle.

The purpose of the invention is to increase reliability and safety.

This aim is achieved in that in a hydraulic drive mechanism -samosvala tilting vehicle, comprising a double acting tipping cylinders, the dispenser being communicated by corresponding hydraulic line E to the pumps, hydraulic reservoir, and rodless rod cavities of hydraulic cylinders, a control switchgear, check valves, mounted in hydrolines between rodless cavities of hydraulic cylinders and a distribution device, with rodless cavities communicating with Roebuck through the bypass solenoid valve, a bypass valve configured to control the hydraulic cavity communicating with cavities rodless cylinders, and the bypass solenoid valve with an electromagnet duplicated lift control valve control switchgear.

The drawing shows a schematic diagram of the proposed hydraulic drive tipping mechanism of the truck-dump truck.

The hydraulic actuator contains pumps 1 and 2, switchgear 3, including lift spool 4 and lower spool 5, lift control spool 6, lower control spool 7, relief valve 8, check valves 9, Control valve including overflow 11, safety valve 12 and valves lowering 13 and braking 14 connected to double-acting tilt cylinders having a rod 16 and piston 17 cavity, hydraulic tank 18. All elements, with the exception of the bypass valve 8, are standard devices am BelAZ trucks.

In the static position, the pumps 1 and 2 supply the working fluid from the hydraulic tank 18 through the switchgear 3 to the steering circuits. When this piston cavity 17 hydraulic cylinders 15 through the bypass valve 8 communicated with the hydraulic tank 18. In this case, the cargo platform is omitted.

When an electric signal is applied to the electromagnet of the slide valve 6 of the elevation control, the latter moves to the extreme left position in the drawings. At the same time, the bypass valve 8, to which the electromagnet receives a control signal interlocked with the signal to the lift control spool 6, moves to the upper position in the drawing, disconnecting the piston cavity 17 of the hydraulic cylinder 15 from the drain to the hydraulic tank 18.

Under the action of the pressure of the working fluid flowing through the slide valve 6 of the lift control into the end cavity of spool 5, the latter moves to the extreme right position in the drawing and communicates the discharge lines of pumps 1 and 2 with the piston cavity 17 of the hydraulic cylinders 15 / end cavity of the overflow valve 8. Thus hoisting platform.

To hold the load platform in an intermediate position, the electrical signal is turned off from the magnet of the lift spool 6, and therefore from the electromagnet of the relief valve 8. At the same time, the latter is held in the upper position of the drawing by the pressure of the working fluid in the end cavity connected

with a piston cavity 17 hydraulic cylinders 15. The lifting control spools 6 and the lowering 7 are kept in the initial position under the influence of return springs, which are connected to the drain of the hydraulic control lifts and lowering spools. The latter are moved to the initial position and the pressure lines of pumps 1 and 2 are disconnected from the hydraulic cylinders 15. The loading platform is held in an intermediate position by means of check valves 9.

To lower the load platform, an electrical signal is applied to the electromagnet of the lower control slide valve 7. The latter is moved to the leftmost position in the drawing. The valve spool 4 moves to the extreme right position, the lowering valve 13 is opened under control action and connects the piston cavity 17 of the hydraulic cylinders 15 with a drain to the hydraulic tank. As the pressure in the piston cavity 17 and, consequently, in the end cavity of the relief valve 8, decreases, the latter, under the influence of the return spring, moves to the lower position in the drawing.

When disconnecting the electrical force from the electromagnet of the lower control spool 7, the latter is moved to the left position, the lowering valve 13 is closed, and the relief valve 8 provides the connection of the piston cavity 17 of the hydraulic cylinders 15 with the drain when the load platform is lowered.

The connection of the piston cavity of the hydraulic cylinders with the drain into the hydraulic tank with the cargo platform lowered ensures a new quality of the object — an exception to the spontaneous lifting of the cargo platform, which increases the reliability of the hydraulic drive of the tilting mechanism and ensures the safety of the car dump truck.

Claims (1)

Claims of the invention A hydraulic drive of an overturning vehicle of a dump truck containing two-way tilting hydraulic cylinders, a switchgear communicated by corresponding hydraulic lines with pumps, a hydraulic tank, and rod and rodless cavities of hydraulic cylinders, a control switchgear, check valves mounted in the hydraulic lines and hydroelectric cylinders mounted on the hydraulic lines of the hydraulic cylinders, control valves, check valves installed in the hydraulic lines of the hydraulic cylinders, valve-mounted hydraulic distributors, check valves installed in the hydraulic cylinders and rodless cylinders. hydraulic cylinders and a distribution device, with rodless cavities communicating with the hydraulic tank through SKNOU solenoid valve, characterized in that, in order to increase reliability and safety relief valve is a hydraulic control cavity communicating with cavities rodless cylinders, and the bypass solenoid valve with an electromagnet controlling duplicated rise control switchgear.