Method of limiting flow in response to sensed pressure
AssigneeDeere & Company
InventorsGrant R. Henn, Aaron R. Kenkel, Doug M. Lehmann
Life of this patent
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Abstract
A method of controlling hydraulic fluid flow to an implement of a material handling vehicle includes coupling a boom arm to a vehicle frame for rotation about the vehicle frame, rotating a boom arm with respect to the vehicle frame with an actuator, coupling an attachment to the boom arm for rotation with respect to the boom arm, sensing a pressure of fluid in the actuator, communicating the sensed pressure to a control system, determining a baseline pressure of the attachment based upon the sensed pressure of the fluid in the actuator, and limiting fluid flow to the actuator with a control valve in response to the sensed pressure of the fluid in the actuator being above the baseline pressure.
Claims20
A material handling vehicle comprising:
- a vehicle frame;
- a boom arm having a first end and a second end, the boom arm coupled to the frame adjacent the first end for rotation with respect to the frame;
- an actuator coupled to the vehicle frame and the boom arm for moving the boom arm with respect to the frame;
- an attachment coupled to the boom arm adjacent the second end of the boom arm;
- a fluid reservoir fluidly coupled to the actuator to control movement of the attachment;
- a control system configured to direct movement of the attachment in response to input from a user;
- a control valve positioned between the fluid reservoir and the actuator to selectively limit flow to the actuator and to thereby control a speed of movement of the attachment;
- and
- a pressure sensor configured to sense a pressure of fluid in the actuator and to communicate the sensed pressure to the control system;
- wherein the control system is operable to compare the sensed pressure to a baseline pressure, and
- wherein the control system is operable to adjust the control valve to limit fluid flow to the actuator in response to the sensed pressure of the fluid in the actuator being above the baseline pressure by a pre-determined amount.
A method of controlling hydraulic fluid flow to an implement of a material handling vehicle, the method comprising:
- coupling a boom arm to a vehicle frame for rotation about the vehicle frame;
- rotating a boom arm with respect to the vehicle frame with an actuator;
- coupling an attachment to the boom arm for rotation with respect to the boom arm;
- sensing a pressure of fluid in the actuator;
- communicating the sensed pressure to a control system;
- determining a baseline pressure of the attachment based upon the sensed pressure of the fluid in the actuator;
- and
- limiting fluid flow to the actuator with a control valve in response to the sensed pressure of the fluid in the actuator being above the baseline pressure.
A control system for a material handling vehicle having a boom arm coupled to a vehicle frame for rotation about the vehicle frame, an actuator coupled to the vehicle frame and the boom arm to cause the boom arm to rotate about the vehicle frame, and an attachment coupled to the boom arm for rotation with respect to the boom arm, the control system comprising:
- a controller configured to determine a baseline pressure based upon the sensed pressure of the fluid in the actuator;
- a sensor configured to sense a pressure of fluid in the actuator and to communicate the sensed pressure to a control system;
- and
- a control valve configured to selectively limit flow to the attachment,
- wherein the controller is configured to compare the sensed pressure to the baseline pressure and is configured to adjust the control valve to limit flow to the actuator in response to the sensed pressure of the fluid in the actuator being above the baseline pressure.
Dependencies are inferred from the claim text.