US 11,834,810 B2
System and methods for cycle time management
Charles Young, Bismarck, ND (US); Marty Carpenter, Bismarck, ND (US); Scott Becker, Bismarck, ND (US); Douglas Kallas, Mandan, ND (US); Matthew Kaldor, Bismarck, ND (US); and Eric Zabel, Bismarck, ND (US)
Assigned to CLARK EQUIPMENT COMPANY, West Fargo, ND (US)
Filed by Clark Equipment Company, West Fargo, ND (US)
Filed on Sep. 20, 2022, as Appl. No. 17/948,544.
Application 17/948,544 is a continuation of application No. 17/030,836, filed on Sep. 24, 2020, granted, now 11,447,930.
Claims priority of provisional application 62/904,860, filed on Sep. 24, 2019.
Prior Publication US 2023/0071137 A1, Mar. 9, 2023
Int. Cl. E02F 9/22 (2006.01); F15B 11/05 (2006.01); E02F 9/20 (2006.01)
CPC E02F 9/2203 (2013.01) [E02F 9/2029 (2013.01); E02F 9/2232 (2013.01); E02F 9/2235 (2013.01); E02F 9/2296 (2013.01); F15B 11/055 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A power machine comprising:
a frame;
a lift arm pivotally mounted to the frame;
a hydraulic actuator coupled to the frame and to the lift arm and actuable to move the lift arm relative to the frame;
a hydraulic system including a pump in communication with the hydraulic actuator, the pump being powered by an engine and being configured to operate with continuously variable displacement to provide a hydraulic flow to the hydraulic actuator; and
a control device configured to:
determine an engine speed value; and
control a run-time displacement of the pump, based on the determined engine speed value, to maintain a predetermined target hydraulic flow rate from the pump to cause the hydraulic actuator to move the lift arm from a fully lowered position to a fully raised position over a predetermined target duration of time corresponding to the predetermined target hydraulic flow rate.
 
9. A method for controlling operation of a power machine, the method comprising:
operating a pump of a hydraulic system, using power from an engine of the power machine, to provide hydraulic flow to execute hydraulic work functions, the pump being configured to operate with continuously variable displacement to provide the hydraulic flow;
determining, using a control device, an engine speed value;
controlling, using the control device, a run-time displacement of the pump, based on the determined engine speed value, to provide hydraulic flow to execute at least one of the hydraulic work functions,
receiving, at the control device, an operator input to control execution of the at least one of the hydraulic work functions; and
during the execution of the at least one of the hydraulic work functions and with the engine at the determined engine speed value, maintaining the run-time displacement of the pump to provide a constant target hydraulic flow rate, corresponding to the determined engine speed value, over a range of operator inputs that command execution of the at least one of the hydraulic work functions with different cycle times.
 
16. A hydraulic work system for use in a power machine with an engine, the hydraulic work system comprising:
a hydrodynamic work actuator circuit that includes a pump that is configured to provide hydraulic flow to execute hydraulic work functions, the pump being powered by the engine and being configured to operate with continuously variable displacement to provide the hydraulic flow; and
a control device that is configured to:
determine a target maximum hydraulic flow rate of the pump for execution of at least one of the hydraulic work functions;
determine an engine speed value;
receive an operator input to control execution of the at least one of the hydraulic work functions; and
independent of the operator input, control a run-time displacement of the pump based on the determined engine speed value, over a range of engine speed values and, to prevent a run-time flow rate of the pump from exceeding the target maximum hydraulic flow rate during execution of at least one of the hydraulic work functions.