CS201584B1 - Double-capacity safety device - Google Patents

Description

The invention provides a circuit for permanently setting two differently large operating pressure safety values in the hydraulic circuit of the machine.

The hitherto known connection for permanently setting two differently large values of working fluid safety pressure in one hydraulic circuit with the possibility of choosing any value considers the connection of two indirectly controlled safety valves to the pressure branch of the circuit and to one of these, with a lower safety pressure value. it is necessary to install a shut-off valve to disable the valve.

In this connection, the nominal orifice of the valve must correspond to the maximum quantity of working hydraulic fluid transported when the hydraulic valves are of robust construction.

The circuit according to the invention does not consider a separate indirectly controlled relief valve consisting of a robust pressure balanced discharge valve and a miniature design outside the controlled relief control valve, which determines the opening characteristic of the valve, i.e. liquid discharge into the drain, but only with a safety valve. directly controlled, i.e. dimensionally small, since the hydraulic fluid flow rate is small and, therefore, the shut-off valve is also miniature in size and construction is simple. A robust indirectly controlled safety valve is built-in to set a higher working pressure relief pressure

201 584

201 SB4 valve, that is, with a drain valve and a minlatum directly controlled safety valve controlling and a booster which drains the liquid into the waste when reaching the initial value is controlled by two directly controlled insurance! By opening or closing the shut-off valve connected upstream of the directly controlled relief valve with a lower setpoint, the hydraulic circuit is provided with either a higher or lower relief pressure, while the discharge of the liquid is always carried by an overflow valve of the indirectly controlled relief valve.

The hydraulic circuit consists of a hydraulic generator 1 connected by a branch 2 with a hydraulic tank 2 »a branch 4, and an indirectly controlled relief valve J5 and a branch 6 with a distributor unit 2. Distribution unit 2 It is a branch 8, SlstlSom 2 connected with a tank 2 and branches 10,13 ^ with hydraulic motor 12.

Branch 12, for 3-way control of the indirectly controlled relief valve 2 and connected to a directly controlled relief valve 14 which is connected by a branch 15 to a shut-off valve 16 and a branch 17 with a hydraulic tank 2 ·

The pressure fluid is led from the generator 1 through a branch 4 to an indirectly controlled paddle valve 2 ® through a branch 6, via a unit 2 » ^{8 through} branches 10, 11 to a hydraulic motor 12. The maximum working pressure of hydraulic fluid in the hydraulic motor 12 Or the value set on the directly controlled relief valve 14, which must be the same as that of the valve 4. If it is desirable that the hydraulic motor 12 operates at a higher relief pressure, that is, the value set on the veritile 2 ' If it is necessary for the hydraulic motor 12 to operate at a lower value of the relief pressure, the valve 16 is opened and the hydraulic circuit is provided with a value set on the directly controlled relief valve 14 which controls the discharge function of the valve 5.

Claims (1)

OBJECT OF THE INVENTION Two-range safety device for permanently adjusting two different pressure levels in one hydraulic circuit, with the possibility to use only one pressure relief value, characterized by the fact that it contains branch A3 / indirectly controlled safety valve / 5 / which is connected to directly controlled safety valve A4 /, which is branch A5 / connected to shut-off valve A6 /, from which the other branch A7 / is led to the tank / 3 /.