Hydraulic fluid warm-up

摘要

A work vehicle including a hydraulic circuit having a cooled return line with a cooler, a bypass return line that bypasses the cooler on the cooled return line, and a controller that electronically controls the flow of hydraulic fluid between the cooled return line and the bypass return line.

主权项

1. A work vehicle including:
a chassis; at least one traction device supporting the chassis; at least one hydraulic actuator coupled to the chassis; a hydraulic circuit configured to operate the at least one hydraulic actuator and to selectively effect initial warm-up of a source of hydraulic fluid, the hydraulic circuit including:
a source of hydraulic fluid;a delivery device in fluid communication with the source of hydraulic fluid;a flow control valve coupled in fluid communication with the delivery device and with the at least one hydraulic actuator and being operable to selectively deliver hydraulic fluid to, and to receive return fluid from, the at least one hydraulic actuator;a return line coupled for receiving return fluid from the flow control valve and for returning the return fluid to the source of hydraulic fluid;the return line being branched into a first return line branch and a second return line branch;said first return line branch including a normally closed, pressure responsive first flow control device and a cooler connected in series with each other, the first flow control device allowing the hydraulic return fluid to travel along the first return line branch when a pressure in the first return line branch immediately upstream of the first control device exceeds a cracking pressure of the first flow control device;said second return line branch bypassing the first flow control device and the cooler on the first return line branch, the second return line branch including a pressure responsive second flow control device, the second flow control device allowing the hydraulic fluid to travel along the second return line branch when the return fluid immediately upstream of the second flow control device exceeds a second cracking pressure of the second flow control device; anda controller in communication with at least one of the first and second flow control devices and being operable when cooling of the return fluid is not desired to adjust at least one of the first and second cracking pressures to cause the first cracking pressure to be relatively higher than the second cracking pressure so that the return fluid flows through the second return line branch to the hydraulic fluid source by way of the second flow control device and bypasses the first flow control device and the cooler.