Boom telescopic buffer hydraulic system and crane

Abstract

The invention discloses a hydraulic system for telescopic buffer of a crane boom and a crane. The hydraulic system for telescopic buffer of the crane boom comprises a telescopic oil cylinder, a main valve and a balance valve, wherein a first working oil port and a second working oil port of the main valve are respectively connected to a rod chamber of the telescopic oil cylinder and a free oil inlet of the balance valve in a communication way, a free oil outlet of the balance valve is connected to a rodless chamber of the telescopic oil cylinder in a communication way, and the first working oil port is also connected to a control oil port of the balance valve in a communication way through a control oil line; and the hydraulic system for telescopic buffer of the crane boom also comprises an auxiliary pressure-relief oil line, a through flow damper and a hydraulic control pressure-relief on-off valve, wherein the oil inlet end of the auxiliary pressure-relief oil line is connected to the rodless chamber of the telescopic oil cylinder in a communication way, the through flow damper and the hydraulic control pressure-relief on-off valve are arranged on the auxiliary pressure-relief oil line, and the control oil port of the hydraulic control pressure-relief on-off valve is connected to the control oil line or the first working oil port in a communication way. By implementing the hydraulic system, impact generated by the balance valve or a pressure shunting damper when the crane boom is started to be shrunk can be effectively reduced.

Description

technical field [0001] The invention relates to the technical field of boom hydraulic control, in particular to a boom telescopic buffer hydraulic system and a crane. Background technique [0002] In the field of cranes in recent years, a boom with a single telescopic oil cylinder (single-cylinder pin-type boom for short) has appeared. Arm, the piston rod of the telescopic oil cylinder is connected to the basic arm, the cylinder barrel is provided with a cylinder head, and two corresponding cylinder pins are arranged on both sides of the cylinder head, and the central axis of the two cylinder pins is connected with the center of the telescopic oil cylinder. The shafts are coplanar, and the cylinder barrel of the telescopic oil cylinder can selectively lock or release its relative position with any section of the telescopic arm when the above-mentioned cylinder pin is stretched out or retracted. In addition, arm pins are provided between adjacent telescopic booms and between...

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Problems solved by technology

Furthermore, the inventor found after in-depth analysis that the reason for the above phenomenon is that when the telescopic oil cylinder 3 of the single-cylinder bolt-type boom is retracted, the high-pressure oil in the rod cavity 311 builds up pressure rapidly, while the rodless The oil in the cavity 312 must pass through the sequence spool 22 of the balance valve 2 to return oil, but the existence of the partial pressure damper 23 delays the opening of the sequence spool 22 of the balance valve 2, which causes the rodless cavity 312 to quickly suppress pressure , when the sequence spool 22 of the balance valve 2 is opened, the instantaneous release of the pressure in the rodless cavity 312 will produce an impact, thereby affecting the stability of the boom when the boom is retracted

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