SU433277A1 - - Google Patents

Description

This invention relates to cit .; Lindram double action, mainly for hydraulic excavators, construction, road machines and other machines with hydraulic power,

The known hydraulic system for controlling the power hydraulic actuator includes an pump, a distributor with levers CONTROL, double-acting hydraulic cylinders, pressure and drain magastrals.

The purpose of the invention is to provide a double-speed reaim of operation of double action cylinders when the rods of hydraulic cylinders are extended,

For this purpose, a check valve and a dual-mode valve with different end cavities, one of which is connected to the discharge line, are installed on the drain pipe, and the other with a switching device with a pressure or drain lines, for example, a three-way valve, moreover, the three-way valve is interlocked with the control levers of the distributor. In addition, a check valve is installed in front of the check valve.

On $ u. I shows a schematic diagram of the proposed hydraulic system; in fig. 2 is a simplified version of a hydraulic system for use on hydraulic machines with a mechanically driven stroke (for example, for mounted excavators).

Vadrosistema includes pump I valve 2, dual-mode valve 3, check valve 4, three-way valve 5, hydraulic 6 and y and the shut-off valve 8;

In the case of a dual-mode spool 3, four cavities are made; To the middle cavity A of the body of a dual-mode spool 3, the drain line from raspeelenitel 2 is connected; Another medium cavity B of the dual-core valve housing 3 is connected to the drain line 6aKv. To the end face of the cavity. In gold 1ik d, the injection line is constantly podmyuchena. The opposite end cavity G of the spool 3 is connected to the three-way edge 5, which B depends on the position of the spools of the distributor 3 and connects the cavity G to the discharge or discharge. Check valve 4 can be performed. as VKa3aHo is higher, in one run with double-valve spool, or execute and connect it separately to the hydraulic system with such a system that if the drain is blocked with two spool 3, it will bypass the fluid from the discharge line to the discharge pressure if the discharge pressure exceeds the discharge pressure and accelerate the movement. If this is not necessary, then access of the fluid to the Hoiviy valve is blocked by a shut-off valve 8, controlled either separately or manually, or through bolts from the spool valve. The hydraulic system works in the next / 1 way. When the spool of the distributor 2 is in a neutral position, the working fluid from the distributor is supplied to the cavity A of the housing of the double-acting valve 3, but since the cavities A and B are separated by a two-valve spool, the pressure in the delivery line rises. At the same time, pressure rises in cavity B, which is permanently connected to the injection line. At the same time, the bottom spool presses the spring 9 and connects the cavities A and B and the working fluid freely flows to the tank. When one of the gold cylinders of the distributor of cylinder 6 is turned on, non-retraction of the stem of the injected working fluid is supplied to the rods of the cavity of cylinder 6 and simultaneously to cavity B of the dual-mode gold 3, cavity G, as in the neutral position of the spools. distribution of bodies, connected, naprshler through a three-way valve 5 with a drain. At the same time, even with small external resistances, an increase in pressure in the injection system will open access to the working fluid to drain through the cavities A and B of the dual-mode valve 3. In the event of a dilution in the injection line or full pressure in it, the pressure switch .. with its own weight) a part of the liquid slave from the drainage of the external void cavity of the cylinder, pressing the spool of brotherly valve 4, will flow over the pressure line, raise its pressure. When the pressure increases in the injection system, therefore, in the cavity B a two-horizontal ALOTNIK 3, compressing the spring 9, connects cavity A with cavity B; When turning on the gold distributor 2 of the stroke motor 7 for the toga, so that when driving down the slope of the machine, it is not accelerated to start, and Taiae in those cases where accelerated lowering of the actuator under co6cTBemfflivi weight is not required, access of the liquid to the reverse valve 4 is blocked 8, When the valve 2 of the cylinder 6 is turned on, the rod simultaneously extends the three-way valve 5 to connect the cavity G of the double-acting valve 3 to the discharge, disengaging it from the drain, and the working fluid is injected Since the drain from the rod cavity is blocked by a dual-mode valve 3 (cavities A and B are separated), the working fluid, due to the pressure difference in the cylinder cavities, will press the valve of the check valve 4 and flow from the rod cavity to the external valve, The following forces act on the spool 3: on one side of the spool, the spring force 9 is equal to the product of the area difference of the cross sections of the spool 3 in the A band by the pressure in it, and the force equal to the product of the pressure on the end face of the ashes from the cavity in cavity D, these forces tend to close the access of the working fluid from cavity a to cavity b of the dual-mode valve, on the other hand the force equal to the product of the injection pressure on the area of the valve core in cavity b, which seeks to connect cavities a and b The cross-sectional areas of spool 3 are chosen so that, at elevated injection pressures, the drainage of fluid by the dual-spool valve is open, and at lower pressures, it is blocked.

AND REQUIRED EFFECTS OF THE INVENTION I. Hydraulic system for controlling the power hydraulic actuator, including pump, distributor with control levers, double-acting hydraulic cylinders, discharge and drain lines, in order to ensure the supply of hydraulic actuators. Explicit reassha work when vvodvizhenizh stocks gidotsidshzhUov, on the drain pipe | G stopped

non-return valve and chromium impeller with face cavities, one of which is connected to the discharge line, and the stem is

an injection and discharge magastral with a three-way switching valve, for example, a three-way crane, the three-way valve being locked with control levers

distributor

2. A device according to claim I, characterized in that a stop valve is installed in front of the check valve.