Abstract:
An agricultural system including a tractor and an implement powered by the tractor. The implement having a plurality of hydraulic fluid using devices, at least one transducer, and a communications device. The transducer is configured to generate a signal representative of a hydraulic load requirement of the plurality of hydraulic fluid using devices. The communications device conveying the signal to the tractor. The tractor is configured to alter a hydraulic fluid characteristic supplied to the implement dependent upon the signal.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to agricultural implements, and more particularly to hydraulic load sensing systems of agricultural implements. 
     2. Description of the Related Art 
     Farmers utilize a wide variety of implements, including seeding implements such as drills and planters. In a known type of planting implement, seed planting or row units are attached to a toolbar extending transverse to the direction of planting. The toolbar is coupled to a tractor or other work vehicle suitable for pulling the planting implement along a field that is to be seeded to a crop. Each planting unit includes a ground penetrating assembly that shapes the bottom and sides of the seed trench, and a seed metering device provides individual seeds at a controlled rate for deposit in the seed trench. Furrow closing components of each row unit close the seed trench in a controlled manner. 
     The planter typically will have at least one hydraulic motor to run a fan for the movement of seed and at least one hydraulic seed drive motor, each having a variable hydraulic fluid use. These and other hydraulic fluid using devices on the implement use pressurized hydraulic fluid supplied by the tractor pulling the implement. The tractor may have a hydraulic pump with a variable output capability. The current art includes using hydraulic lines or hoses to communicate the load requirements to a control on the planter. This poses some difficulty to effectively do as the implements have increased in size requiring longer and longer hydraulic lines that have inherent losses and response delays. 
     What is needed in the art is a more cost effective and quicker response load control system for implements. 
     SUMMARY OF THE INVENTION 
     The present invention provides an implement load sensing and control system for an agricultural implement, and more particularly a planter having transducers that electronically resolve the load requirements. 
     In one form thereof, the invention is directed to an agricultural system including a tractor and an implement powered by the tractor. The implement having a plurality of hydraulic fluid using devices, at least one transducer, and a communications means. The transducer is configured to generate a signal representative of a hydraulic load requirement of the plurality of hydraulic fluid using devices. The communications means convey the signal to the tractor. The tractor is configured to alter a hydraulic fluid characteristic supplied to the implement dependent upon the signal. 
     In another form, the invention is directed to an agricultural implement powered by a tractor. The implement includes a plurality of hydraulic fluid using devices, at least one transducer, and a communications means. The transducer is configured to generate a signal representative of a hydraulic load requirement of the plurality of hydraulic fluid using devices. The communications means conveys the signal to the tractor. The tractor is configured to alter a hydraulic fluid characteristic supplied to the implement dependent upon the signal. 
     An advantage of the present invention is that the hydraulic load is quickly resolved and conveyed to the tractor. 
     Another advantage of the present invention is that it eliminates long hydraulic lines used for load control. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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 embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a perspective view of an agricultural seed planting implement; 
         FIG. 2  is a schematic representation of a load sense system and other elements in one embodiment of the present invention used on the implement of  FIG. 1 ; and 
         FIG. 3  is a schematic representation of a load sense system and other elements in another embodiment of the present invention used on the implement of  FIG. 1 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, and more specifically to  FIG. 1  in particular, a seed planting implement  10  is shown. Seed planting implement  10  has a frame that includes a tow bar assembly  12  having a tow bar  14  and a connection assembly  16  at the longitudinally forward end thereof configured for mating with a corresponding hitch of a tractor or other work vehicle (not shown) for pulling seed planting implement  10  through a field. A laterally extending toolbar  18  is generally transverse to tow bar  14  and thereby generally transverse to the direction implement  10  is towed during planting operations. A plurality of seed planting units (or row units)  20  are connected to toolbar  18  in a side by side relationship, each of the seed planting units (row units) being substantially identical to the others. In the exemplary embodiment shown, seed planting implement  10  includes sixteen seed planting units  20 , only some of which are identified with reference numbers; however, it should be understood that more or fewer seed planting units can be provided on a particular seed planting implement. 
     Each seed planting unit  20  is connected to toolbar  18  by upper and lower arms. Each seed planting unit  20  extends rearward from toolbar  18  to plant a row of seeds as seed planting implement  10  is towed across a field by tractor  22 . The individual planting units  20  are spaced along toolbar  18  to provide planted seed rows of a desired spacing. During a planting operation, forward movement of seed planting implement  10  causes each seed planting unit  20  to form a seed trench, deposit equally spaced seeds in the seed trench and close the seed trench over the deposited seeds. 
     A seed metering system receives seeds from a seed hopper and provides individual seeds at a controlled rate to a seed tube for deposit in the bottom of the seed trench. Bulk tanks  42  contain seed and perhaps fertilizer or chemicals that are metered to, or proximate to, the seed trench. A vacuum system includes a fan/motor  40  that provides vacuum to a seed metering system for the operation of the seed metering system. A seed trench closing mechanism  50  at the trailing end of each seed planting unit  20  closes the seed trench after the seeds have been deposited in the seed trench. Seed trench closing mechanism  50  may include a pair of pinch wheels that operate on opposite sides of the seed trench to move soil back into the seed trench and over the seeds deposited in the bottom of the seed trench. A trailing press wheel travels along the top of the closed seed trench and firms the soil replaced in the seed trench. 
     Now, additionally referring to  FIGS. 2 and 3  there are shown schematical representations of two hydraulic load sensing systems  24  and  124  that resolve the highest load requirement and conveys that information to tractor  22 , which supplies pressurized hydraulic fluid to implement  10  based on the information. 
     Now looking at  FIG. 2 , there is illustrated a hydraulic load sensing system  24  where a transducer  26  senses a load by having pressurized fluid from multiple parts of planter  10  conveyed thereto, through valves  34 . Illustrated here, there are seed drive motors  38 , and fan motors  40  in two different sections and a bulk fill fan  46  located at another section of implement  10 . These separate sections will have a load that requires a determinable amount of hydraulic fluid flow at a specific pressure to fulfil their individual load requirements. This load requirement is conveyed to transducer  26  by way of valves  34 , which may be shuttle valves or other suitable valves that will allow the highest load need to be conveyed to transducer  26 . Transducer  26  generates a signal representative of the load requirement and conveys the information by way of a communications means  36  represented here as a signal line  36 , to tractor  22 . The output of signal line  36  may be a synthesized hydraulic pressure that serves as the signal, particularly for the sake of compatibility with legacy tractor control systems. 
     In turn tractor  22  receives the signal from signal line  36  and uses that information to compensate the pressure and flow of the hydraulic fluid generated by a hydraulic pump coupled to an engine in tractor  22 , to thereby produce adequate power to run implement  10 . An advantage of the present invention is that the hydraulic needs of implement  10  can be met without the need to generate, by default, a constant higher pressure fluid supply. This reduces the energy losses that are experienced by less robust control systems. 
     Now, additionally looking at  FIG. 3 , there is illustrated a hydraulic load sensing system  124  that has many of the same elements as system  24 . Here instead of having one transducer  26 , there are three transducers  28 ,  30  and  32 , each respectively assigned to one of the sections previously discussed. In this embodiment of the present invention, each transducer  28 ,  30  and  32  generates an individual signal, with them being electronically resolved to ultimately present one signal, by way of signal line  36 , to tractor  22 . The resolution of the signal is to present the highest result as the signal on signal line  36 . Signal line  36  may be an electronic signal conveyed by a wire, a wireless electronic signal, or the signal may be presented in some other medium, such as a fluid or air. More specifically, the signal from the transducer(s) is converted into a current command to a duplicator valve  48  at the front of planter  10  or on tractor  22 . The duplicator valve  48  uses supply oil from the power beyond line to create a duplicated hydraulic pressure signal the same as the highest load signal on the planter. 
     With the prior art the distance between the planter and the tractor is too long to provide a hydraulic hose between the load and the source to properly control a pressure compensated load sense system. In contrast the present invention uses pressure transducer(s)  26 ,  28 ,  30  and  32 , depending upon the embodiment, to capture the highest load pressure, and convert that to an electronic signal that is sent to a valve either on the front of planter  10  or on tractor  22  which can convert/duplicate that hydraulic pressure into the hydraulic load sense signal circuit. 
     These long distances between a prior art planter and tractor  22  make it difficult to use a hydraulic hose to effectively communicate the load signals between the planter and tractor. This prevents the signal being used to control the tractor and therefore taking advantage of the efficiencies available from a pressure flow compensating (PFC) load sensing system. 
     In the present invention pressure transducer  26  or a group of pressure transducers  28 ,  30  and  32  are used by hydraulic load sensing system  24  or  124  at the toolbar of implement  10 . Depending on the pressure transducer used, the system pressure can be resolved hydraulically thru a chain of load sense check valves  34  which communicate to one transducer  26 , as in system  24  or a group of transducers  28 ,  30 ,  32  may be used, as in system  124 , with the highest pressure signal is resolved electronically at the controller. The oil supplied to the transducer controlled circuits on implement  10  will come from the power beyond connection on tractor  22 . The power beyond connections are a grouping of pump supply, return, and load sense signal inputs. 
     The pressure transducer (single or multiple arrangement) provides an electronic signal to the implement  10  controller  56 . Controller  56  converts the signal into a current command to the duplicator valve  48  at the front of planter  10  or on tractor  22 . The duplicator valve  48  uses supply oil from the power beyond line, or pump supply, to create a duplicated pressure signal the same as the highest load signal on the planter. The duplicated signal (if higher than the load sense signal circuit on the tractor) will communicate back to the PFC pump, thereby altering the hydraulic fluid pressure presented to implement  10 . 
     Duplicator valve  48  may be located in a valve manifold  52  coupled to implement  10 , or duplicate valve  48  may be located on tractor  22 . Valve manifold  52  is used to control power beyond flow. When tractor  22  is running power beyond is always pressurized and is able to flow oil. A solenoid operated check valve in valve manifold  52  blocks flow from getting out to the planter and running continuously. 
     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.