SU1230975A1 - Hydraulic drive of self-propelled jib crane - Google Patents

Description

The invention relates to lifting machines and can be used in jib self-propelled cranes with retractable counterweights.

The purpose of the invention is to increase reliability,

The drawing shows a diagram of the hydraulic self-propelled boom crane.

On base machine 1 there is an arrow 2, hydraulic cylinder 3 lifting and lowering the boom with hydraulic lock 4, hydraulic cylinder 5 extending the counterweight with spring 6, counterweight 7. The cavities of the hydraulic cylinder 3 lifting and lowering the boom are connected through a three-position distributor 8 with a source 9 of pressure (pump) and tank 10. The piston 11 of the hydraulic cylinder 5 of advancing the counterweight is spring-loaded from the side of the rod cavity, which is communicated by the atmosphere. The piston cavity of the hydraulic cylinder 5 of the counterweight is communicated through a controlled two-position three-line distributor 12, respectively, with the piston cavity of the hydraulic cylinder 3 raising and lowering the boom and with the tank 10. The controlled two-position three-line distributor 12 is hydraulically controlled and its control cavity will be replaced with a post. the cavity of the hydraulic cylinder 3 lifting and lowering the boom The hydraulic actuator includes a valve 13, a safety valve 14 and a filter 15.

The hydraulic actuator of the self-propelled boom crane operates as follows. In the transport position, the boom of the crane is on a support. The spool of the three-position distributor 8 occupies the neutral position, at which the channels informing the three-way distributor 8 with the cavities of the hydraulic cylinder 3 of raising and lowering the boom are closed. The piston cavity of the gyro-cylinder 5, the displacement of the counterweight, is communicated through a controlled two-position three-way valve 12 s, with tank 10, and a syringe valve with atmosphere, hydraulic cylinder 5

Compiled by Editor I. Casard Techred O.Go

Order 2515/26 Circulation 799 Subscription

VNIIPI USSR State Committee

for inventions and discoveries - 113035, Moscow, Zh-35, Rauschska nab. d. 4/5

. Production and printing enterprise, Uzhgorod, st. Design, 4.

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The counterweight is in the extreme left position under the action of the spring 6.

To bring the boom into working condition, the spool of the three-position distributor 8 is moved to the right. The working fluid is supplied from a pressure source 9 (pump) through a three-position valve 8 and a hydraulic lock 4 into the piston cavity of the hydraulic cylinder 3 raising and lowering the boom and into the control cavity of the controlled two-position three-line distributor 12. Spool of the controlled two-position three-line distributor 12 under the action of working pressure the fluid moves up and connects the piston cavities of the hydraulic cylinders 3 and 5. The piston of the hydraulic cylinder 5 increases the counterweight, overcoming the force of the spring 6, still to the right and pushing the counterweight 7. The counterweight remains extended while the boom is in the operating position, i.e. while in the piston cavity of the hydraulic cylinder 3 for raising and lowering the boom a certain pressure of the working fluid remains. When the boom is lowered into the transport position, it is placed on the support and the load on the rod of the hydraulic cylinder 3 of raising and lowering the boom ceases to act. Therefore, the pressure in the piston cavity of the hydraulic cylinder 3 drops. At the same time, the pressure in the control cavity of the controlled two-position three-way distributor 12 drops, the spool of which lowers and connects the piston cavity of the hydraulic cylinder 5 to move the counterweight to the tank 10. The piston of the hydraulic cylinder 5 to move the counterweight under the action of the spring 6 returns the counterweight 7 to its original position.

Thus, the counterweight is automatically raised when the boom is brought into working condition and automatically returned after the boom is set to the transport position

Proofreader S. Shekmar

Claims (1)

HYDRAULIC SYSTEM OF A SELF-PROPELLED BOOM CRANE, containing a hydraulic cylinder for raising and lowering the boom, the cavities of which are communicated through a three-position distributor with a pressure source and a tank, a hydraulic cylinder for extending the counterweight, controlled by a two-position three-line distributor, one of whose inputs is connected to the tank, and a hydraulic lock , in order to increase reliability, the controlled two-position three-way valve is made with hydraulic control, its control cavity and the second input are communicated with. the piston cavity of the hydraulic cylinder for lifting and lowering the boom, and the exit is with the piston cavity of the counterweight extension hydraulic cylinder, the piston of the latter being spring-loaded from the rod cavity side. 1230975 ²