Engineering machinery and locking valve of front working device of engineering machinery

Abstract

The invention provides engineering machinery and a locking valve of a front working device of the engineering machinery; the locking valve is connected between a cavity of a hydrocylinder of the front working device and a high-pressure oil pipe, the locking valve comprises a first oil path for connecting the cavity and the high-pressure oil pipe; a two-position valve arranged on the first oil path, wherein the two-position valve comprises a first position for uniaxially conducting the first oil path so as to only allow the hydraulic oil to uniaxially flow to the cavity from the high-pressure oil pipe, and a second position for bidirectionally conducting the first oil path; and a control position for enabling the two-position valve to be at the first position in a normal state and enabling the two-position valve to be at the second position in a compression state; an overflow valve connected between the cavity and the control position to apply force on the control position when the pressure in the cavity exceeds the predetermined pressure so that the two-position valve is at the second position. The locking device provided by the invention can prevent the working device from suddenly falling, and improves the safety of the engineering machinery.

Description

technical field [0001] The invention relates to construction machinery, in particular to a locking valve of a front working device of the construction machinery. Background technique [0002] Construction machinery includes excavators, loaders, forklifts, etc., which are widely used in engineering fields such as construction, roads, and mines. Construction machinery has front working devices, such as excavator's digging mechanism (including bucket, arm and boom), loader's bucket, forklift's mast, etc. These front working devices need to be controlled by hydraulic pressure. Cylinders for propulsion. [0003] figure 1 It is the outline structure diagram of the excavator in the existing construction machinery, such as figure 1 As shown, the front working device of the excavator mainly includes a bucket (bucket) 110, an arm (arm) 120 and a boom (boom) 130, and these working parts are respectively driven by hydraulic cylinders 111, 121, 131 . [0004] figure 2 It is a sche...

AI Technical Summary

Problems solved by technology

[0005] In practical applications, due to the aging of the oil pipe, excessive pressure or other sudden factors, the high-pressure oil pipe 2 or the high-pressure oil pipe 3 may burst suddenly, and the hydraulic oil in the pipe will flow out from the rupture, and the hydraulic cylinder 1 will be damaged due to lack of hydraulic pressure. Under the action of gravity, the working device of construction machinery will suddenly fall. If there is someone or something under the working device at this time, a safety accident will occur

Images