SU1242592A1 - Hydraulic drive of loader jib - Google Patents

Description

The invention relates to construction machines, namely to hydraulic drives of single-bucket loaders,

The purpose of the invention is to increase loader performance and increase reliability by reducing dynamic loads.

The drawing shows the hydraulic boom loaders

The hydraulic actuator contains a hydraulic distributor 1 connected by a hydraulic motor with power hydraulic cylinders 2 boom lifts, a hydraulic pump 3 and a tank. Hydropneumatic damper 4 is connected via parallel-connected non-return valve 5 and throttle 6 with the hydraulic distributor 1 and through the check valve 7 with the tank, and through the hydraulic valve 8 and throttle 9 with the hydraulic accumulator 10. Hydraulic accumulator 10 is connected with two hydraulic lines with hydraulic distributor 1 and one of They are equipped with a check valve 11, and in the other there are series-connected throttle 12 and hydraulic valve 13 with a control chamber connected to the lowering cavity of the power hydraulic cylinders 2 booms. In addition, the hydroaccumulator 10 communicates with the tank through a hydraulic valve 14, the inlet of which and the control chamber are connected to the hydroaccumulator 10, and the outlet to the tank.

The hydraulic actuator works as follows.

In the neutral position of the valve of the hydraulic distributor 1, the hydraulic pump 3 and the rod end of the hydraulic cylinders 2 communicate with the tank, and the piston cavities through the check valve 5 and the throttle 6 communicate with the damper 4. With a stationary loader, the boom is also stationary, and the pressure of the working fluid in the piston cavities of the hydraulic-- cylinders 2 and in the damper 4 has the same value determined by the external load, i.e. strength of work equipment and load. With the beginning of the movement of the loader on the unevenness of the bearing surface of the emergence of the vertical, the vertical oscillations of the machine and the forces of inertia appear.

Consider the boom movements when the working equipment of the loader oscillates relative to the base machine. In the case of boom movement, under the action of inertial forces down, the working fluid from the piston cavities gi, cylinders 2 through the hydraulic distributor, non-return valve 5 and throttle 6 is displaced into the damper 4. The volume of the damper 4 allows to provide a slight movement of the pistons of the hydraulic cylinders 2, which is not enough to soften the sharp dynamic loads transmitted to the elements of the hydraulic drive and working equipment. Stock

the cavities of the hydraulic cylinders 2 are at this time communicated with the tank and unhindered filling; potts the working fluid. In the case of a double boom boom under the action of inertial forces upward, the working fluid

from the rod cavities of the hydraulic cylinders 2 are displaced into the tank, and the piston cavities are filled with working fluid from the tank through the check valve 7 and partially from. the damper 4 through the throttle 6. When the limiting pressure is exceeded in the damper 4, the value of which is established by the spring of the hydraulic valve 8, the excess working fluid through this hydraulic valve and the throttle 9

enters hydroaccumulus 10 and charges it.

To lower the boom, the spool valve 1 is lowered down by the operator and connects the hydraulic pump

3, hydroaccumulator 10 through a check valve 11 with rod cavities of hydraulic cylinders 2, booms, and their piston cavities, through throttle 12 and opened hydraulic valve 13, with a hydraulic accumulator 10. Control chamber of a hydraulic valve 13 is connected to a lowering cavity of hydraulic cylinders 2 and a hydraulic valve opens with increasing Htm pressure of the working fluid in these cavities. The hydroaccumulator 10 is charged when it is lowered from the third due to the potential energy of gravity of the working equipment. When the maximum pressure in the hydroaccumulator 10 is exceeded, the value of which is established by the spring of the hydraulic valve 14, the working fluid through this valve is drained into the tank.

To raise the boom, the spool and distributor I from the neutral position - itqi H rises up by the operator and connects the hydraulic pump, .. 3 and the hydraulic accumulator 10 through the check valve 11 to the piston cavities of the power hydraulic circuits 2, and the rod cavities with the tank. The energy stored in hydroav: cumul torus 10 is used for along the;: boom boom with load.

312425924

The fourth position of the spool hydraulic pump of the hydraulic pump and the overlap of the distributor I ensures that;

talcum channels of the hydrodistributor,

hydraulic pump load and overlap

talcum channels of the hydrodistributor,

P

Claims (1)

LOADER BOOM HYDRAULIC, including a control valve connected by hydraulic lines to power hydraulic cylinders. hydraulic pump, hydraulic accumulator, hydraulic valves, non-return valves and throttles, about γ l and h and u u and I with what, for the purpose. to increase the productivity of the loader, it is equipped with a hydropneumatic damper connected through a parallel installed first check valve and a first throttle valve, through a second check valve with a tank and through a series mounted first hydraulic valve and a second throttle valve with a hydraulic line, which is connected to the hydraulic accumulator, with the tank through the second hydraulic valve, with one of the working branches of the control valve through the third check valve and with the other working branch of the control valve through the Tel'nykh installed third hydraulic valve and a third choke, wherein the control chamber 'of the first; and the third hydraulic valves are respectively communicated with the hydropneumatic damper and with the rod cavity of the power hydraulic cylinder.