Patent Application
20180192575
The present invention relates to towed agricultural implements, and more specifically to steerable towed implements.
As agricultural technology advances toward greater efficiencies, the need for a greater lateral reach of an implement becomes increasingly important. This is because a single pass will result in a greater area being either tilled, planted or harvested. With such significant lateral spans, it becomes necessary for an implement that is towed to have steering to enable the tractor or other towed vehicle to negotiate around obstacles and through tight corners. Typically, this is done with a set of actuators, usually hydraulic, operating on steerable wheels for the implement and that are controlled through a hydraulic control system located on the tractor. In simplified form, the implement steering is in response to direct operator input from the tractor operator to negotiate turns at the end of a pass in the field or to negotiate around obstacles. As the operator negotiates a corner, the operator then lines up the implement for another pass and in this case is busy with a number of inputs, including the steering of the towed implement to a neutral position.
It has been proposed in a number of systems to provide elaborate control systems responsive to a great many inputs to return the implement steering to a neutral position. These systems respond to a variety of parameters including implement velocity and other operational factors. While they do provide a measure of self-centering, they do so with greatly increased complexity and cost.
Accordingly, what is needed in the art is a simplified system for returning a steerable towed implement to a center position.
The present invention seeks to bring a towed steerable implement to a neutral position in a simplified and cost effective fashion.
In one embodiment, an implement steering system is provided for use with a towable implement. The system includes an actuator connected to at least one steerable axle on the towable implement and an actuator control system connected to the actuator for executing steering commands of an operator between right and left stop limits and a neutral position. A sensor is connected to the actuator to generate a signal to the actuator control system proportional to the position of the actuator between the right and left limits and a neutral position reflecting straight ahead steering of the towable implement. The actuator control system is configured to receive signals from the sensor to control the actuator to its neutral position in the absence of an operator control input.
In another embodiment, a towing vehicle is provided with a towed implement having steerable ground support wheels. Actuators are provided for the steerable wheels to control the direction of the towed implement. The towing vehicle has an actuator control system connected to the actuator for executing steering commands of an operator between right and left stop limits and a neutral position. A sensor is connected to the actuator for generating a signal to the actuator control system proportional to the position of the actuator between right and left limits and a neutral position reflecting straight ahead steering of the towable implement. The actuator control system is configured to receive signals from the sensor to control the actuator to its neutral position in the absence of an operator control input.
Still another embodiment is directed to a method for controlling an implement towed by a tractor and receiving operator steering inputs to steer between a right and left stop limit and a neutral position. The method includes determining whether an operator steering input is provided to the implement and, in the absence of an operator steering input, steering the implement to a neutral position.
One advantage of the present embodiment is freeing an operator to concentrate on aligning a towed implement after a turn or obstacle avoidance maneuver.
Another advantage is providing a simplified and cost effective system to achieve automatic centering of a towed implement.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawing, wherein:
The exemplification set out herein illustrates one embodiment of the invention and such exemplification is not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and more particularly to
The frame 20 is supported by a pair of wheel assemblies 24 each having a wheel assembly frame 26 connected to frame 20 in a fashion that permits upwards and downward movements relative to frame 20 so as to control the depth of penetration of the cultivator ground engaging components or seeding units carried by the frame 20. Each wheel assembly frame 26 has a steerable wheel mounting 28 about a vertical pivot axis 30 through crank arms 32. A left actuator 34 and right actuator 36 are connected to the crank arms 32 to provide synchronized steering of the wheels 35 through a tie bar 37.
Left and right actuators 34 and 36 are illustrated as hydraulic. It should be apparent, however, to those skilled in the art that the actuators 34 and 36 may be pneumatic or electric as appropriate for a particular control protocol. Left actuator hydraulic lines 38 and right actuator hydraulic lines 40 lead to an implement control module 42 (also referred to as UCM or Universal Control Module) that directs hydraulic pressure to the left and right actuators 34 and 36, as appropriate, to steer the wheel assemblies 24 and thus the frame 20. The implement control module 42 is provided with pressurized hydraulic fluid from the tractor 14 by a line 44. An operator control module 46, positioned in operator cab 18 on tractor 14, sends command signals to the implement control module 42 through line 48. Although one line is illustrated, it should be apparent that more than one line may be utilized according to the control protocol.
In operation, the operator in cab 18 directs the tractor 14 through a field and can provide manual inputs to the implement steering by the operator control module 46. The actuator control system is connected to the actuators 34 and 36 for executing steering commands of an operator between right and left stop limits and a neutral position in between the right and left stop limits. The neutral position is approximately halfway between the right and left stop limits but may be either side depending upon the crown of a roadway or the ground over which the implement is towed.
In the illustrated simplified form, the operator control module 46 utilizes manual inputs from the operator to steer implement 10 at the end of a pass to achieve a tighter turning radius or to avoid an obstacle. In the case of turning at the end of a pass, the operator, in this simplified manual steering, must not only bring the implement 10 to the field towed position but must accurately steer the tractor 14 onto the adjacent rows. With prior art simplified steering systems, the overload of control movements may cause tracking of the implement to be difficult.
In accordance with a present embodiment, the control system set forth below allows for unassisted centering of the implement after an end of a pass. Continuing to refer to
As shown in
The above apparatus provides autosteering only when needed, thus allowing for a simplified control system in lieu of complicated control schemes which incorporate expensive components and software execution. As a result, an operator is provided with an automatic self-centering feature on a simplified steering assembly with its associated less costly acquisition and simplified operation.
While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
