SU1481346A1 - Bulldozer - Google Patents

Abstract

The invention relates to a bulldozer and allows to increase the reliability and reduce the energy consumption of its work. The bulldozer contains the base machine 1, the blade 2, the pusher bar 3 and the hydraulic control of the blade 2. The pusher bar 3 is connected to the base machine 1 via hydraulic cylinders (GC) 14 and 15, each of which is made with one working cavity and with a spring. The hydraulic actuator includes the main hydraulic distributor (GR) 5, additional hydraulically controlled GR 7, compensatory GC 6, hydroaccumulator (HA) 26 and hydro-pneumatic dampers 20, 21. Each of them communicates with the working cavity HZ 14, 15. The latter through check valves 16 and 17 communicates with the drain, and GA 26 is connected via a hydraulic valve 28 to the pumping station and through a safety hydraulic valve 27 to the drain. When the resulting external load on the blade is displaced toward the pushing bar 3 HZ 15, the pressure of the working fluid increases in its piston cavity, which is transmitted to the control chamber 9 of the GR 7, the spool of which moves to the left. The rod cavity GC 6 is connected through state GR 5 with GA 26, and the piston cavity with a drain. The HZ 6 rod is retracted and creates a force that compensates for the displacement of the resultant external load. The spool gg 7 returns to its original position. Harsh dynamic loads acting on the blade 2 are perceived by HZ 14 and 15 and absorbed by dampers 20 and 21 through throttles 18 and 19. A part of the working fluid is displaced through hydraulic valves 22, 23 and check valves 24, 25 in GA 26. The potential energy stored GA 26 is used to drive an HZ 6. 1 sludge.

Description

one

This invention relates to earth moving machinery, namely bulldozers.

The purpose of the invention is to increase reliability and reduce energy consumption.

The drawing shows a hydraulic control of the blade.

The bulldozer has a base machine 1, a blade 2, pushes bar 2 and a hydraulic actuator containing hydraulic cylinders 4 for raising and lowering the blade, communicated by their cavities with the main hydraulic distributor 5, and a pump unit. At an angle to the longitudinal axis of the bulldozer, a hinge but connecting the blade and the base machine are equipped with a compensation hydraulic cylinder 6, which communicates with its cavities through the main valve 5 with an additional hydraulically controlled valve 7. Chambers 8 and 9 control through adjustable throttles 10 and 11 and valves 12 and 13 communicated with the cavity of the hydraulic cylinders-sensors 14 and 15 installed in the pushing bars x 3. The hydraulic cylinders-sensors 14 and 15 are provided with springs in the piston cavities and communicated through check valves 16 and 17 with a hydraulic tank and through p Adjustable throttles 18 and 1 9 - with hydropneumatic dampers 20 and 21, which through hydraulic valves 22 and 23 and check valves 24 and 25 communicate with the hydraulic accumulator 26. The last communicated with one hydraulic line with the hydraulic distributor 7, the other through the hydraulic valve 27 - with

plum, and the third hydroline through the hydraulic valve 28 - with a pressure hydraulic line.

In the initial position, the external load on the blade of the bulldozer is absent or evenly distributed along its length and the pressure of the working fluid in the cavities of the hydraulic cylinders-sensors 14 and 15 are the same, therefore the valve of the hydraulic distributor 7 takes a neutral position. The hydroaccumulus torus is 26 s-ar, and the spool valve 5 is in a neutral position.

The bulldozer works as follows.

When developing a soil with a bulldozer, a resultant external load on the dump occurs. This is due to the unevenness of the strength properties of the soil, the occurrence of cleavage of the soil, as well as the features of the workflow technology. Let, for example, at some moment of time result in an external load on

0, the blade is displaced towards the pushing bar with the hydraulic cylinder sensor 15, causing the blade to skew. In the piston cavity of the said hydraulic cylinder, as well as in the hydropneumatic damper 21 and in the control valve 9 of the control valve 7, the pressure of the working fluid increases compared with the pressure in the cylinder of the sensor-14 cylinder. As a result of this increase in pressure, the control valve 7 moves to the left and communicates through the control valve

5 piston cavity compensation cylinder 6 with hydraulic accumulator 26, and the piston cavity with a drain. Rod compensation cylinder

6W is bent and creates a force that compensates for the displacement of the resultant external load, which ensures the equalization of the forces perceived by the pushing bars and the equalization of pressure in the cavities of the hydraulic cylinders-sensors 14 and 15. The spool valve 7 returns

to its original position, i.e. in a neutral position, and held there until the next imbalance of the system. In the event that at another time point the resulting external load is displaced towards the pushing bar with the hydraulic cylinder-sensor 14, the valve of the hydraulic distributor 7 is displaced to the right and connects the pinhole of the compensating hydraulic cylinder 6 with the hydraulic accumulator 26, and the rod cavity to the drain. The rod of the hydraulic cylinder 6 extends and again compensates for the action of an offset external load, equalizing the forces perceived by the push bars. The equalization of forces perceived by the pushing bars reduces the bending stresses in the heap and the pushing bars of the bulldozer, which increases their reliability. The sharp dynamic loads acting on the bulldozer blade are perceived and absorbed by the hydropneumatic dampers 20 and 21 through the throttles 18 and 19. The volume of the cavities of the dampers 20 and 21 is selected based on the damping of the external load and, in its absence, there is no excessive pressure in the cavities of the dampers. With a sharp dynamic load, the pressure in the dampers rises and a part of the working fluid is displaced through the hydraulic valves 22 and 23 and check valves 24 and 25 into the accumulator 26. The pistons of the hydraulic cylinders 14 and 15 return to their initial position after removal

reducing the external load under the action of pressure from the hydropneumatic dampers 20 and 21 and the springs located in the piston cavities of the hydraulic cylinders-sensors 14 and 15. The feeding of the hydraulic cylinders-sensors 14 and 15 is carried out through check valves 16 and 17. Hydropneumatic

Q dampers absorb kinetic energy, which reduces the stresses in the elements of the working equipment, and at the same time converts kinetic energy into potential,

5 which is stored in the hydroaccumulator and then used for the drive. compensation cylinder, compensating for the uneven distribution of external load on the working

Q equipment.

Claims (1)

Invention Formula A bulldozer, including a base car, a tire, a blade, pushes of a bar and a hydraulic control of the blade, containing hydraulic cylinders for raising and lowering the blade, communicated through the main control valve to the pumping unit, installed at an angle to the longitudinal axis of the bulldozer and hinged to the blade and the base machine compensating hydraulic cylinder, the cavities of which through an additional hydraulically controlled hydraulic distributor communicate with the pressure source, hydraulic cylinders-dump skew sensors, the cavities of which communicate with the chambers An additional hydraulic control valve, characterized in that, in order to increase reliability and reduce the energy consumption of its work, the pushes of the bars are connected to the base machine through hydraulic cylinders-sensors, each of which is made with one working cavity and with a spring installed in it, form, hydroaccumulator, and the hydraulic actuator is equipped with hydro-pneumatic dampers, each of which is connected to the working cavity of the corresponding hydraulic cylinder-sensor, while the working cavity of each hydro ilindra sensor sooobschena 5 through reverse valve with a drain and by sequentially adjusting hydraulic valve and another check valve - with a pressure reservoir torus which posred0 five 0 five 0 514813466 The operation of another hydraulic valve is connected to a safety hydraulic valve with a pump installation and by means of a drain.