Abstract:
A downforce controller for an agricultural implement having a double-acting hydraulic cylinder. The cylinder is configured to be coupled to an agricultural row unit and an agricultural toolbar for transmitting a net downforce between the agricultural toolbar and the agricultural row unit. A first pressure in a first chamber of the cylinder and a second pressure in a second chamber of the cylinder have counteracting effects on the net downforce. A manifold coupled to the cylinder is in fluid communication with the first chamber. A pressure control valve coupled to the manifold is in fluid communication with the manifold and the first chamber.

Description:
BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1A  is a perspective view of an embodiment of a downforce controller. 
       FIG. 1B  is a side elevation view of the embodiment of the downforce controller of  FIG. 1A . 
       FIG. 1C  is a cross-sectional view of the downforce controller of  FIG. 1A . 
       FIG. 2A  is a side elevation view of an embodiment of a planter row unit incorporating the downforce controller of  FIG. 1A . 
       FIG. 2B  is a side elevation view of an embodiment of a planter and a tractor drawing the planter row unit of  FIG. 2A  through a field. 
       FIG. 3  schematically illustrates an embodiment of an electronic control system for controlling one or more downforce controllers. 
       FIG. 4  is a top view of an embodiment of a fluid control system for controlling multiple downforce controllers. 
       FIG. 5  is a cross-sectional view of another embodiment of a downforce controller including a lift pressure control valve. 
       FIG. 6  is a top view of another embodiment of a fluid control system for controlling multiple downforce controllers. 
       FIG. 7  is a fluid schematic illustrating an embodiment of a manifold for controlling pressure delivered to a downforce controller. 
    
    
     DESCRIPTION 
     Downforce Controller 
     Referring now to the drawing figures, wherein like reference numerals designate identical or corresponding parts throughout the several views,  FIGS. 1A-1C  illustrate an embodiment of a downforce controller  100 . Referring to  FIG. 1A , the downforce controller  100  includes a manifold  110  and a cylinder  130 . The manifold  110  preferably includes a manifold body  102 , a lift control conduit  120 , and a cavity (not shown) sized to receive a down pressure control valve  140 . The manifold body  102  preferably includes a supply passage  112 , a return passage  114 , and a lift control passage  116 . Each passage  112 ,  114 ,  116  preferably includes a left fitting, a right fitting, and an aperture connecting the left and right fittings. Referring to the cross-sectional view of  FIG. 1C , the manifold body  110  preferably includes a control pressure diagnostic passage  118  and a down chamber connection passage  111 . 
     The cylinder  130  includes a barrel  132 , a rod  170 , and a gland  138 . The cylinder  130  is mounted to the manifold  110 . In the embodiment illustrated in  FIGS. 1A-1C , the barrel  132  is mounted to the manifold body  102 . Referring to the cross-sectional view of  FIG. 1C , the gland  138  is mounted to a lower end of the barrel  132  and the rod  170  is slidably mounted within the gland  138 . The rod  170  includes a piston  174  which separates an interior volume of the barrel  132  into a down chamber  136  and a lift chamber  134 . 
     The down pressure control valve  140  is preferably a electro-hydraulic pressure reducing-relieving valve. The down pressure control valve  140  preferably includes a solenoid  142  having an electrical port  144 . The down pressure control valve  140  preferably includes a flow control valve  150  having a supply port  152 , a return port  154 , and a control port  158  ( FIG. 1C ). The pressure control valve  140  is preferably a PDR08-P proportional pressure relief valve available from Hydac International GmbH in Sulzbach, Germany (“Hydac”). The down pressure control valve  140  is preferably mounted to the manifold body  102 . The down pressure control valve  140  is preferably oriented substantially parallel with the cylinder  130 . 
     Referring to  FIG. 1C , the supply port  152  of the pressure control valve  140  is in fluid communication with the supply passage  112 . The return port  154  is in fluid communication with the return passage  114 . The control port  158  is in fluid communication with the control pressure diagnostic passage  118 . The control pressure diagnostic passage  118  is in fluid communication with the down chamber connection passage  111 . The down chamber connection passage  111  is in fluid communication with the down chamber  136 . The control pressure diagnostic passage  118  and the down chamber connection passage  111  collectively comprise a passage placing the control port  158  in fluid communication with the down chamber  136 . The conduit  120  places the lift control passage  116  in fluid communication with the lift chamber  134 . The control pressure diagnostic passage  118  is preferably capped with a cap  119  which may be removed in order to place a gauge, transducer, or other pressure measurement device in fluid communication with the control port  158 . 
     In operation, the flow control valve  150  establishes a control pressure at the control port  158  by selectively allowing flow between the control port  158 , the supply port  152 , and the return port  154  as is known in the art. The solenoid  142  changes an operating state of the down pressure control valve  140  (e.g., by imposing a force on a component of the flow control valve  150 ) to modify the control pressure as is known in the art. The control pressure set by the solenoid  142  preferably corresponds to a signal received at the electrical port  144 . 
     Implement Installation and Operation 
     Turning to  FIGS. 2A and 2B , an embodiment of the downforce controller  100  is illustrated installed on a planter  10  drawn by a tractor  5 . The planter  10  includes a transversely extending toolbar  14  to which multiple row units  200  are mounted in transversely spaced relation. 
     For attachment purposes, the manifold body  102  of the downforce controller  100  includes a pin eye  182  ( FIGS. 1A-1C ) and the rod  170  includes a clevis  172 . Referring to  FIG. 2A , a controller attachment bracket  214  is mounted to the front bracket  212 . The downforce controller  100  is pivotally connected to the controller attachment bracket  214  by an upper pin  215 - 1  extending through the pin eye  182 . The downforce controller  100  is pivotally connected at a lower end to a parallel linkage  216  by a lower pin  215 - 2  extending through the clevis  172 . A manifold  700  is preferably mounted to the toolbar  14 . 
     Continuing to refer to  FIG. 2A , the parallel linkage  216  supports the row unit  200  from the toolbar  14 , permitting each row unit to move vertically independently of the toolbar and the other spaced row units in order to accommodate changes in terrain or upon the row unit encountering a rock or other obstruction as the planter is drawn through the field. A ride quality sensor  364 , preferably an accelerometer, is mounted to the row unit  200  and disposed to measure the vertical velocity and acceleration of the row unit  200 . Each row unit  200  further includes a mounting bracket  220  to which is mounted a hopper support beam  222  and a subframe  224 . The hopper support beam  222  supports a seed hopper  226  and a fertilizer hopper  228  as well as operably supporting a seed meter  230  and a seed tube  232 . The subframe  224  operably supports a furrow opening assembly  234  and a furrow closing assembly  236 . 
     In operation of the row unit  200 , the furrow opening assembly  234  cuts a furrow  38  into the soil surface  40  as the planter  10  is drawn through the field. The seed hopper  226 , which holds the seeds to be planted, communicates a constant supply of seeds  42  to the seed meter  230 . The seed meter  230  of each row unit  200  is preferably selectively engaged to a drive  372  via a clutch  370  such that individual seeds  42  are metered and discharged into the seed tube  232  at regularly spaced intervals based on the seed population desired and the speed at which the planter is drawn through the field. The drive  372  and clutch  370  may be of the types disclosed in U.S. patent application Ser. No. 12/228,075, incorporated herein in its entirety by reference. A seed sensor  360 , preferably an optical sensor, is supported by the seed tube  232  and disposed to detect the presence of seeds  42  as they pass. The seed  42  drops from the end of the seed tube  232  into the furrow  38  and the seeds  42  are covered with soil by the closing wheel assembly  236 . 
     The furrow opening assembly  234  preferably includes a pair of furrow opening disk blades  244  and a pair of gauge wheels  248  selectively vertically adjustable relative to the disk blades  244  by a depth adjusting mechanism  268 . The depth adjusting mechanism  268  preferably pivots about a downforce sensor  362 , which preferably comprises a pin instrumented with strain gauges for measuring the force exerted on the gauge wheels  248  by the soil  40 . The downforce sensor  362  is preferably of the type disclosed in Applicant&#39;s co-pending U.S. patent application Ser. No. 12/522,253, incorporated herein in its entirety by reference. In other embodiments, the downforce sensor is of the types disclosed in U.S. Pat. No. 6,389,999, incorporated herein in its entirety by reference. The disk blades  244  are rotatably supported on a shank  254  depending from the subframe  224 . Gauge wheel arms  260  pivotally support the gauge wheels  248  from the subframe  224 . The gauge wheels  248  are rotatably mounted to the forwardly extending gauge wheel arms  260 . 
     Referring to  FIG. 2B , a GPS receiver  366  is preferably mounted to an upper portion of the tractor  5 . A monitor  310  is preferably mounted in a cab  7  of the tractor  5 . One or more speed sensors  368 , such as a Hall-effect wheel speed sensor or a radar speed sensor, are preferably mounted to the tractor  5 . 
     Electrical Control System 
     Turning to  FIG. 3 , an electrical control system  300  for controlling and measuring downforce and other implement functions is illustrated schematically. In the electrical control system, the monitor  310  is preferably in electrical communication with the down pressure control valves  140  and a lift pressure control valve  740  (described herein with respect to  FIG. 7 ), as well as the drives  370  and the clutches  372 . The monitor  310  is preferably in electrical communication with the downforce sensors  362  as well as the seed sensors  360 , the downforce sensors  362 , the speed sensors  368 , and the GPS receiver  366 . 
     The monitor  310  preferably includes a central processing unit (“CPU”)  316 , a memory  314 , and a graphical user interface (“GUI”)  312  allowing the user to view and enter data into the monitor. The monitor  310  is preferably of the type disclosed in Applicant&#39;s co-pending U.S. patent application Ser. No. 13/292,384, the disclosure of which is hereby incorporated herein in its entirety by reference, such that the monitor is capable of displaying downforce and seeding information to the user. 
     Downforce Fluid Control System 
     Turning to  FIG. 4 , an embodiment of a fluid control system  400  is illustrated installed on four downforce controllers  100  (each installed on a respective row unit  200 ), the toolbar  14  and the tractor  5 . The fluid control system includes a supply  430 , preferably a power-beyond supply port located on the tractor  5 , and a tank  440 , preferably a power-beyond tank port (not shown) located on the tractor  5 . The supply  430  and tank  440  are in fluid communication with the manifold  700 . 
     Turning to  FIG. 7 , an embodiment of the manifold  700  is illustrated schematically. The manifold  700  includes a filter  710  (preferably model no. CP-SAE-120 available from Hydac), a check valve  720  (preferably model no. RV16A-01 available from Hydac), and the lift pressure control valve  740  (preferably an equivalent valve to the down pressure control valve  140 ). The supply  430  is in fluid communication with the filter  710 , a pressure port of the lift pressure control valve  740 , and a supply hose  422  connected to a supply port of the manifold  700 . The tank  440  is in fluid communication with the check valve  720 , a tank port of the lift pressure control valve  740 , and a return hose  424  connected to a return port of the manifold  700 . A control port of the lift pressure control valve  740  is preferably in fluid communication with a lift control hose  426  connected to a lift control port of the manifold  700 . 
     Returning to  FIG. 4 , the supply hose  422  is in fluid communication with the supply passage  112  of the first downforce controller  100 - 1 . The supply passage  112  of each downforce controller  100  is in fluid communication with the supply passage  112  of an adjacent downforce controller  100  via an inter-row supply hose  412 . The distal port of the supply passage  112  of the distal downforce controller (e.g., the right-hand port of the supply passage of the downforce controller  100 - 4  as illustrated in  FIG. 4 ) is preferably capped with a cap  450 . 
     The return hose  424  is in fluid communication with the return passage  114  of the first downforce controller  100 - 1 . The return passage  114  of each downforce controller  100  is in fluid communication with the return passage  114  of an adjacent downforce controller  100  via an inter-row return hose  414 . The distal port of the return passage  114  of the distal downforce controller (e.g., the right-hand port of the return passage of the downforce controller  100 - 4  as illustrated in  FIG. 4 ) is preferably capped with a cap  450 . 
     The lift control hose  426  is in fluid communication with the lift control passage  116  of the first downforce controller  100 - 1 . The lift control passage  116  of each downforce controller  100  is in fluid communication with the lift control passage  116  of an adjacent downforce controller  100  via an inter-row lift hose  416 . The distal port of the lift control passage  116  of the distal downforce controller (e.g., the right-hand port of the lift control passage of the downforce controller  100 - 4  as illustrated in  FIG. 4 ) is preferably capped with a cap  450 . 
     Operation 
     In operation of the fluid control system  400  and the electronic control system  300 , the monitor  310  preferably receives a downforce signal from each downforce sensor  362 . The monitor  310  preferably uses the downforce signal to display the downforce measured at each row unit  200 . The monitor  310  preferably uses the downforce signal to select a target net downforce to be applied to each row unit  200  by each downforce controller  100 . For example, if the downforce signal for a given row unit  200  is in excess of a threshold, the monitor  310  preferably reduces the target net downforce to be applied by the corresponding controller  100 . In other embodiments, the monitor  310  allows the user to simply select a target net downforce for each downforce controller  100 . Once the target net downforce is selected for each downforce controller, the monitor  310  preferably sends control signals to each down pressure control valve  140  and the lift pressure control valve  740  such that the net downforce applied by each downforce controller  100  more closely approximates the corresponding target net downforce. In some embodiments, the monitor  310  selects desired control pressures according to the methods disclosed in Applicant&#39;s co-pending U.S. patent application No. 61/515,700, incorporated herein in its entirety by reference. 
     Downforce Controller—Alternative Embodiments 
     Turning to  FIG. 5 , an alternative embodiment of a downforce controller  500  is illustrated in cross-section. The downforce controller  500  includes a manifold  510  and a conduit  520 , allowing incorporation of an individual lift control valve  140 - 1  to control the pressure in the lift chamber  134 . The individual lift pressure control valve  140 - 1  is preferably substantially similar to the pressure control valve  140 . It should be appreciated that the right hand side of the manifold  510  is similar to the manifold  110  except that the lift control passage  116  is preferably omitted. 
     The manifold  510  preferably includes a manifold body  502 , a lift control conduit  520 , and a cavity sized to receive the individual lift pressure control valve  140 - 1 . The manifold body  502  preferably includes a supply passage  512  and a return passage  514 . Each passage  512 , 514  preferably includes a left fitting, a right fitting, and an aperture connecting the left and right fittings. The manifold body  510  preferably includes a control pressure diagnostic passage  518  and a down chamber connection passage  511 . 
     The supply port of the individual lift pressure control valve  140 - 1  is in fluid communication with the supply passage  512 . The return port of the individual lift pressure control valve  140 - 1  is in fluid communication with the return passage  514 . The control port of the individual lift pressure control valve  140 - 1  is in fluid communication with the control pressure diagnostic passage  518 . The control pressure diagnostic passage  518  is in fluid communication with the down chamber connection passage  511 . The down chamber connection passage  511  is in fluid communication with the down chamber  136 . The control pressure diagnostic passage  518  and the down chamber connection passage  511  collectively comprise a passage placing the control port of the individual lift pressure control valve  140 - 1  in fluid communication with the down chamber  136 . The conduit  520  places the lift control passage  516  in fluid communication with the lift chamber  134 . The control pressure diagnostic passage  518  is preferably capped with a cap (not shown) which may be removed in order to place a gauge or other pressure measurement device in fluid communication with the control port of the individual lift pressure control valve  140 - 1 . 
     Turning to  FIG. 6 , a modified fluid control system  600  is illustrated installed on four downforce controllers  500  (each installed on a respective row unit  200 ), the toolbar  14  and the tractor  5 . The fluid control system  600  preferably includes the same supply  430  and tank  440  as the fluid control system  500 . 
     The supply passage  112  and return passage  114  of the first downforce controller  500 - 1  are in fluid communication with the supply  430  and the tank  440 , respectively. As with the fluid control system  500 , the supply passage  112  and the return passage  114  of each downforce controller  500  are in fluid communication with the supply passage  112  and the return passage  114 , respectively, of an adjacent downforce controller  500  via the supply hose  412  and the return hose  414 , respectively. 
     Similarly, the supply passage  512  and return passage  514  of the rightmost downforce controller  500 - 4  are in fluid communication with the supply  430  and the tank  440 , respectively. The supply passage  512  and the return passage  514  of each downforce controller  500  are in fluid communication with the supply passage  512  and the return passage  514 , respectively, of an adjacent downforce controller  500  via an inter-row supply hose  612  and an inter-row return hose  614 , respectively. 
     The individual lift control valve  140 - 1  is preferably in electrical communication with the monitor  130 . In operation of the modified fluid control system  600 , the monitor  130  is preferably configured to select pressures of both the lift pressure control valve  140 - 1  and the down pressure control valve  140 - 1 . The monitor  130  is preferably configured to alter the commanded lift pressure and down pressure for each downforce controller  500  based on the downforce signal received from the downforce sensor  362  of the corresponding row unit  200 . 
     In other embodiments of the downforce controller  500 , the down chamber connection passage  511  is in fluid communication with the control port of the lift pressure control valve  140 - 1  via a pilot-operated blocking valve whose pilot pressure port is in fluid communication with the control port of the down pressure control valve  140 - 1  such that lift pressure is only applied when the down pressure exceeds a threshold. Similarly, in other embodiments of the downforce controller  100 , the lift control passage  116  is in fluid communication with the conduit  120  via a pilot-operated blocking valve whose pilot pressure port is in fluid communication with the control port of the down pressure control valve  140  such that lift pressure is only applied when the down pressure exceeds a threshold. In such embodiments, the pilot-operated blocking valve is preferably housed within the manifold body. 
     In other embodiments of the downforce controller  100  and the downforce controller  500 , the down pressure control valve  140  and/or the lift pressure control valve  740  and/or the individual lift pressure control valve  140 - 1  are replaced with a manually operated pressure reducing-relieving valves such that the user may manually select the lift and/or down pressure applied to each row unit  200 . 
     In still other embodiments of the downforce controller  100 , a spring is incorporated in the lift chamber  134  such that the spring is compressed as the rod  170  extends. A bottom of the spring is preferably adjustable from outside the cylinder (e.g., by a lockable sliding mechanism supporting an annular ring on which the spring rests) such that the user is enabled to adjust the compression and reaction force of the spring as the rod extends. In such embodiments, the conduit  120  and lift control passage  116  are preferably omitted. 
     The foregoing description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment of the apparatus, and the general principles and features of the system and methods described herein will be readily apparent to those of skill in the art. Thus, the present invention is not to be limited to the embodiments of the apparatus, system and methods described above and illustrated in the drawing figures, but is to be accorded the widest scope consistent with the spirit and scope of the appended claims.