Patent ID: 9322398
Filing Date: 2016-04-26
CPC Classification: F04B

Claim Text:
1. A concrete pumping structure comprising a first pumping cylinder structure and a second pumping cylinder structure, each pumping cylinder structure comprising a delivery cylinder ( 1 ), a water tank ( 3 ), a driving oil cylinder ( 7 ) having a rodless chamber mouth ( 17 ) at one end and a rod chamber mouth ( 8 ) at the opposite end; wherein the water tank ( 3 ) being positioned between the driving oil cylinder ( 7 ) and the delivery cylinder ( 1 ), the delivery cylinder ( 1 ) being provided with a concrete piston assembly ( 2 ) inside; wherein, during a pumping process, a piston rod ( 6 ) inside the driving oil cylinder ( 7 ) drives the concrete piston assembly ( 2 ) to reciprocate in the delivery cylinder ( 1 ); the concrete pumping structure further comprising a concrete return hydraulic system which controls the two driving oil cylinders and drives the two concrete piston assemblies to return back to their respective water tanks at the same time when the concrete piston assemblies need repair or replacement, wherein each pumping cylinder structure also comprises a limit structure, and during a normal pumping working state, the limit structure limiting and restricting the concrete piston assembly ( 2 ) from returning back to the water tank ( 3 ), and removes the limiting when the concrete piston assemblies need repair and replacement, allowing the concrete piston assemblies to return back to their respective water tanks, wherein the concrete return hydraulic system comprises a concrete return valve assembly ( 30 ) and at least one pressure oil source ( 21 , 23 ), the concrete return valve assembly controlling the at least one pressure oil source ( 21 , 23 ), wherein when the limit structure is in a limiting removed state, oil is supplied to the rod chamber oil mouths ( 8 , 8 ′) of the two driving oil cylinders ( 7 , 7 ′) via a concrete return pipeline ( 18 ) at the same time, and the oil is returned through the rodless chamber oil mouths ( 17 , 17 ′) of the two driving oil cylinders ( 7 , 7 ′) at the same time.