Single-cylinder bolt expansion and contraction control system and construction machine

Abstract

The invention provides a single-cylinder bolt expansion and contraction control system and a construction machine. The single-cylinder bolt expansion and contraction control system comprises a first reversing control valve communicated with an auxiliary oil source; a telescopic oil cylinder comprises a core pipe which is arranged on a cylinder barrel and accommodated in a piston rod; a first oil circuit is connected with the first hydraulic fluid port of the first reversing control valve; a second oil circuit is connected with the second hydraulic fluid port of the first reversing control valve; the oil inlet ends of a first check valve and a second check valve are communicated with the telescopic oil cylinder; one end of a third oil circuit is communicated with the oil outlet ends of the first and the second check valves; and the other end of the third oil circuit is communicated with an electromagnetic ball valve. The core pipe in the telescopic oil cylinder is only used for returning oil during the work process of the single-cylinder bolt expansion and contraction control system. The pressure of return oil is lower, so that the impact on the core pipe is lower, and the service life of the core pipe is prolonged.

Description

technical field [0001] The invention relates to the technical field of engineering machinery, in particular to a single-cylinder bolt telescopic control system and construction machinery with the single-cylinder bolt telescopic control system. Background technique [0002] At present, the telescopic booms of large-tonnage cranes with five or more booms all use a single-cylinder latch telescopic control system to realize the telescopic boom of each boom. The existing single-cylinder bolt telescopic control system uses an external auxiliary oil source, and connects the auxiliary oil source to the pin pulling device through the core tube of the telescopic oil cylinder or the rubber hose reel, and then the pin pulling device controls the cylinder pin and the arm. Pin extraction and locking. [0003] However, when the core tube of the telescopic oil cylinder is connected with the auxiliary oil source for pulling out the pin, in the process of telescopic arm, due to the relative ...

AI Technical Summary

Problems solved by technology

In this way, when the boom speed is too fast, due to the increase in the volume between the core tube and the piston rod, the pressure of the auxiliary oil will become smaller, and even the arm pin will automatically pop out to cause friction and collision with the big arm, causing the arm A safety accident occurs due to the bending of the pin. When the retracting speed is too fast, the pressure of the core tube will increase due to the decrease in the volume between the core tube and the piston rod. Telescopic cylinder scrapped

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