Void protection system

摘要

A void protection system for a mining shovel having an operator input device includes an independent metering valve assembly including one or more fluid source-cylinder valves for fluidly connecting the fluid source to the hydraulic cylinder. The system also includes a sensor assembly for monitoring the fluid pressure within the rod end and the head end of the hydraulic cylinder, and a control module. The control module is configured to monitor movement of the operator input device, monitor pressure within the hydraulic cylinder, increase the opening of the corresponding fluid source-cylinder valve and increase fluid flow from the fluid source to fill corresponding end of the hydraulic cylinder until pressure in the corresponding end of the hydraulic cylinder is above a first threshold pressure.

主权项

1. A mining shovel, comprising:
a boom assembly; a hydraulic cylinder having a rod end and a head end; a dipper coupled to the boom assembly such that movement of the hydraulic cylinder moves the dipper; an independent metering valve assembly coupled to the hydraulic cylinder and to a fluid source, the assembly comprising:
one or more fluid source-cylinder valves each having an opening for fluidly connecting the fluid source to the hydraulic cylinder; an operator input device; a sensor assembly for monitoring the fluid pressure within the rod end and the head end of the hydraulic cylinder; a control module configured to monitor movement of the operator input device and control the hydraulic cylinder based on the movement of the operator input device, and, when there is no movement at the operator input device, to:
monitor pressure within the head end and the rod end of the hydraulic cylinder by receiving signals from the sensor assembly;when the signals indicate that the pressure in the rod end or the head end of the hydraulic cylinder is below a first threshold pressure, increase the opening of the corresponding fluid source-cylinder valve and increase fluid flow from the fluid source to fill the corresponding end of the hydraulic cylinder until the pressure in the corresponding end is above a second threshold pressure; andwhen the signals indicate that the pressure in the rod end or the head end of the hydraulic cylinder is greater than the second threshold pressure, reduce the opening of the corresponding fluid source-cylinder valve and decrease fluid flow from the fluid source.