Abstract:
A harvester load control that increases the efficiency of the harvester and its operator by providing a automatic control unit that monitors minute engine RPM&#39;s caused by varying crop and transport load effects, automatically adjusting the harvester&#39;s ground speed to provide a consistent operational RPM including thrashing, separating and other conditioning services.

Description:
RELATED APPLICATIONS 
       [0001]    The present application is related to U.S. Pat. No. 4,458,471, issued Jul. 10, 1984, by Herwig, included by reference herein. 
         [0002]    The present application is related to U.S. Pat. No. 4,727,710, issued Mar. 1, 1988, by Kuhn, included by reference herein. 
         [0003]    The present application is related to U.S. Pat. No. 6,591,591, issued Jul. 15, 2003, by Coers, included by reference herein. 
         [0004]    The present application is related to U.S. Pat. No. 6,941,736, issued Oct. 13, 2005, by Freeman, included by reference herein. 
         [0005]    The present application is related to U.S. Pat. No. 4,542,802, issued Sep. 24, 1985, by Garvey, included by reference herein. 
     
     FIELD OF THE INVENTION 
       [0006]    The present invention relates to an engine load control and, more particularly, to a load control for hydrostatically or hydraulically driven equipment maintaining a consistent and selectable engine RPM under various loads. 
       BACKGROUND OF THE INVENTION 
       [0007]    Combines and other harvesting equipment encounter extremely wide crop conditions throughout the field. These conditions include varying crop densities, ripeness, moisture content and toughness. All of these conditions affect the way the harvesting machine process the crop. In conditions where the crop suddenly increases in volume, the combine will not process all of the crop causing some of it to be lost out of the back into the field and an other portion to bypass the holding tank to be reprocessed which further compounds the problem. In other circumstances the crop my be lighter in yield which creates a situation where when the machine is adjusted to handle heavier crop can cause the crop to be blown out the rear of the machine by the fans used for cleaning. 
         [0008]    Varying crop yields and harvesting conditions make it difficult for the harvester operator to adjust the machine. When it is adjusted in one portion of the field for that particular location&#39;s conditions it may be way off when the machine gets to another location in the field. This makes for greater crop loss, crop damage and inefficient use of the machine. As the crop lightens the machines engine RPM&#39;s accelerate often furthering the problems just discussed. if the machine is over loaded the engine RPM&#39;s drop resulting in the slowing of the machines thrashing and separating systems adversely affecting their performance. The operator cannot detect the tens of thousands of varying conditions he encounters throughout the day and even if he could he is unable to instantly predict the correct change and make that change. Because of these issues operators and harvesting equipment is often less than efficient resulting in lost crop, lost quality, lost efficiency of labor fuel and more damage to the machine. When sudden crop changes occur that can actually slug the harvester resulting in a sudden drop in RPM the harvester can actually become plugged. This plugging of the machine always results in lost productivity and sometimes results in damage to the machine or danger to the operator. 
         [0009]    Freeman in U.S. Pat. No. 6,941,736 uses a system that monitors the output of the machine and warns the operator though an alarm system. There have been other early warning type designs similar to this that warn when overloads have occurred. Coers in U.S. Pat. No. 6,591,591 uses a system based upon header position. When the header is lowered during cutting the harvester speed is immediately decreased to prevent a sudden increase in material down stream with a reduction equal to the estimated percentage increase in material for the given height change. Garvey in U.S. Pat. No. 4,542,802 uses electonics over hydraulics to control the forward speed of the combine based upon engine droop and two stage govenor. 
         [0010]    Kuhn in U.S. Pat. No. 4,727,710 proposes to maintain the ground speed for harvesting efficiency through an automatic means of maintaining a pre established ground speed. Herwig in U.S. Pat. No. 4,458,471 offers a means of controlling ground speed by identifying the limiting means of the harvester through a plurality of sensors including at least sensors mounted on the ground speed, boost pressure and engine speed 
         [0011]    Other solutions do not take in consideration that the human operator is both too slow and too distracted to respond to manual warning signals. Any operator concentrating for a warning signal, which would occur nearly constantly in fields with varying conditions, would soon become fatigued and confused. They do not free up the operator for more important and controllable occurrences in or out of the harvesting machine that are a fact of operator life in a harvester. 
         [0012]    Kuhn does not take into consideration that ground speed must be varied not maintained in order to maintain a consistent flow of crop materials into the harvester in order to reach maximum efficiency and quality. 
         [0013]    Coers assumes that crop conditions are tied to cutting height, when in fact cutting height is only one of the several parameters that affects the crop load and difficulty of harvest. For example, a crop that is the same height will vary in toughness from early in the morning until mid day, becoming less tough to harvest, thrash and separate as the middle of the day is reached and then reverse itself as the evening falls and due land moisture levels once again increase. 
         [0014]    Herwig proposes multiple sensors which have proven to confuse and complicate the decision making ability of the controller. Ground speed changes for instance will occur in perfectly even crops when the harvester is going up or down a hill as opposed to being run on level ground. Soft ground will provide a greater load than hard ground because of tire sink and traction loss. Even the fuel and grain tank level will create a varying load that will effect ground speed. Boost pressure is also adversely affected because of conditions that are unique to it. Garvey provides no safety measures for over speed or for protecting an operator if the target RPM is reached. The unit is not programmable making it difficult for an operator to set and operate the system. Hydraulic operation prevents the unit from as fast an operation as is required for optimum operation. The Garvey unit does not take into consideration that consistent crop flow through the harvester is paramount to effective operation because it slows the harvester on uphill grades based solely upon transport load and allows the harvester to increase ground speed on downhill slopes again based solely upon transport loads. 
         [0015]    None of the prior art suggests the understanding that only one component on the harvester provides an accurate read when read at extremely high rates to determine its collective conditions, the engine and the engine alone. 
         [0016]    It is therefore an object of the invention to increase the harvesting efficiency of any hydrostatically driven harvester. 
         [0017]    It is another object of the invention to reduce fatigue on the operator. 
         [0018]    It is another object of the invention to reduce down time caused by slugging or breakdowns. 
         [0019]    It is another object of the invention to reduce fuel consumption. 
         [0020]    It is another object of the invention to reduce crop damage due to over thrashing of the crop. 
         [0021]    It is another object of the invention to reduce crop loss do to underlaoding of the harvester. 
         [0022]    It is another object of the invention to increase area harvested by maintaining the maximum speed for the crop conditions. 
         [0023]    It is another object of the invention to reduce operator skill level requirements. 
         [0024]    It is another object of the invention to produce crops acceptable to the pharmaceutical industry through greatly increased crop quality. 
       SUMMARY OF THE INVENTION 
       [0025]    In accordance with the present invention, there is provided a harvester load control that will increase the efficiency of the harvester and its operator by providing a control unit that monitors minute engine RPM changes caused by varying crop and transport load effects, automatically adjusting the harvesters ground speed to provide a consistent operational RPM including thrashing, separating and other conditioning services. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]    A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which: 
           [0027]      FIG. 1  is a left elevation view of a combine type harvester; 
           [0028]      FIG. 2  is a schematic perspective view of a harvester load effects; 
           [0029]      FIG. 3  is a schematic perspective view of a load control operational flow; and 
           [0030]      FIG. 4  is a schematic perspective view of a load control and its components. 
       
    
    
       [0031]    For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0032]      FIG. 1  is a left elevation view of a combine  10  type harvester. 
         [0033]      FIG. 2  is a schematic perspective view of a harvester load effects. 
         [0034]      FIG. 3  is a schematic perspective view of a load control operational flow. 
         [0035]      FIG. 4  is a schematic perspective view of a load control and its components. 
         [0036]    Referring to  FIG. 1 , therein is shown an agricultural harvester comprising a main frame  12  supported for movement by a wheel structure including drive wheels  16  driven by a hydrostatic transmission  18 . The wheel structure depicted could include or be composed of ground engaging tracks or multiples of wheels  16  other than shown. 
         [0037]    A vertically adjustable header or harvesting platform  20  with a cutter bar  21  is used for cutting a standing crop and directing cut material further processing.  FIG. 1  depicts one type of harvester known as a combine  10  which includes crop processing features such as the feeder house  23  that is pivotally connected to the frame  12  and includes a conveyor for conveying the cut material to a beater  22 . The beater  22  directs the material upwardly to a rotary threshing and separating assembly  24 . Other orientations and types of threshing structures and other types of headers, such as transverse frame  12  supporting individual row units, could also be utilized on combines and other types of harvesters such as choppers, windrowers, cotton harvesters, grape harvesters and other hydrostatically driven harvesters for agricultural and pharmaceutical harvesting could be substituted for the example provided. 
         [0038]    The rotary threshing and separating assembly  24  threshes and separates the harvested crop material. Grain and chaff fall through grates on the bottom of the assembly to a cleaning system  26 . The cleaning system  26  removes the chaff and directs the clean grain to a clean grain elevator (not shown). The clean grain elevator deposits the clean grain in grain tank  28 . The clean grain in the tank can be unloaded into a grain cart or truck by unloading auger  30 . 
         [0039]    Threshed and separated straw is discharged from the crop processing unit through outlet  32  to discharge beater  34 . The discharge beater  34  in turn propels the straw out the rear of the combine  10 . It should be noted that the discharge beater  34  could also discharge crop material other than grain directly to a straw chopper. The operation of the harvester is controlled from an operator&#39;s cab or if not manned from an operations center located on the harvester and controlling the harvesters operations from a remote location or robotic control operations. 
         [0040]    In this example the rotary threshing and separating assembly  24  comprises cylindrical rotor  36  housing  38  and a hydraulically driven rotor  36  located inside the housing  38 . The front part of the rotor  36  and the rotor  36  housing  38  define the infeed section  40 . Downstream from the infeed section  40  are the threshing section  42 , the separating section  44  and the discharge section  46 . The rotor  36  in the infeed section  40  is provided with a conical rotor  36  drum having helical infeed elements for engaging harvested crop material received from the beater  22  and inlet transition section  48 . Immediately downstream from the infeed section  40  is the threshing section  42 . In the threshing section  42  the rotor  36  comprises a cylindrical rotor  36  drum having a number of threshing elements for threshing the harvested crop material received from the infeed section  40 . 
         [0041]    Downstream from the threshing section  42  is the separating section  44  wherein the grain trapped in the threshed crop material is released and falls through a floor grate in the rotor  36  housing  38  to the cleaning system  26 . The separating section  44  merges into a discharge section  46  where crop material other than grain is expelled from the rotary threshing and separating assembly  24 . Although the harvester is shown as a combine  10  for harvesting grain, it is to be understood that the present invention may also be utilized with other types of harvesters. 
         [0042]    Harvester speed is controlled automatically by a linear actuator  56  operably connected to the hydrostatic pump or other hydraulically driven transmission hydrostat handle  52 . The controller adjusts a variable position lever at the output pump to drive the wheels  16  at the desired operating speed. The operator can control speed in a manual mode through a conventional hydrostat control handle located in the cab. The operator establishes an upper speed limit for the harvester to prevent runaway of the machine and a lower end speed limit to prevent accidental engagement of the drive wheels  16  when the machine is being serviced and the engine  14  run to operating speed. Both of these functions are provided or safety purpose and not for general operation of the machine. Speed is infinitely variable within the range of the upper and lower speed limits. A speed signal sensor, in a preferred embodiment a Hall Effect sensor, provides signal to the input of the controller. The controller monitors the speed to make safety decisions. If the ground speed  92  is below the minimum safety speed setting the controller will not permit the actuator to move the hydrostat pump  68  lever to increase ground speed  92 . If the controller attempts to increase ground speed  92  to decrease engine  14  RPMs and that would cause a ground speed  92  above the maximum ground speed  94   94  safety setting the controller will not signal the actuator to increase ground speed  92 . It is understood that hydrostat pump  68  is a term used because of its familiarity to harvesters but the invention is to understood to apply to any hydraulically driven type harvesting machine. 
         [0043]    Referring to  FIG. 2 , a system for controlling the drive train of the harvester of  FIG. 1  is illustrated in block diagram form. The output shaft of the engine  14  is connected to the drive wheels  16  of the harvester through a transmission. Most modern harvesters use hydrostatic transmissions, which offer an “infinitely variable” gear ratio between the engine  14  and the drive wheels  16 . As a result, the load imposed on the engine  14  through the transmission, which will be referred to herein as the “transport load  66 ”, can be varied over an “infinite” number of settings within the operating range of the transmission. In effect, the setting of the hydrostatic transmission  18  controls the division of the power output of the engine  14  between the transport load  66  and the processing-harvesting mechanisms coupled to the engine  14  through a power takeoff  72  located between the engine  14  and the hydrostatic transmission  18 . This power takeoff  72  normally has a fixed gear ratio. The load imposed on the engine  14  by the processing-harvesting mechanisms will be referred to herein as the “crop load  70 ”. 
         [0044]    Both the transport load  66  and the processing load are continually changing. By adjusting the setting of the hydrostatic transmission  18  with either changing load conditions, the total actual load on the engine  14  can be adjusted to control the engine  14  speed. For example, if the harvester begins a steep uphill grade, the transport load  66  increases significantly, this will first be addressed by the engine  14  governor. If the engine  14  governor is unable to compensate for the increased engine  14  load then the transmission must be adjusted, the load on the engine  14  can be further controlled by adjusting the setting of the transmission. Similarly, if the density of the processing increases, the crop load  70  increases, but again the engine  14  load can be controlled by adjusting the setting of the transmission to compensate for the increase in processing load by reducing the transport speed of the harvester, thereby reducing the transport load  66  on the engine  14 . 
         [0045]    The setting of the hydrostatic transmission  18  in an operator manned machine is regulated by a control lever which is normally adjusted manually by means of a cable leading to the vehicle cab where it is accessible to the vehicle operator through a suitable control lever or knob. It is moved forward from its neutral position for driving the vehicle in the forward direction, and rearward from its neutral position for driving the vehicle in the reverse direction. As the control lever is moved away from neutral in either direction, it progressively increases the speed ratio between the engine  14  and the transport wheels  16 , which has the effect of increasing the transport load  66  on the engine  14 . 
         [0046]    In accordance with the present invention, a transmission control system “linear actuator  56 ” adjusts the setting of the hydrostatic transmission  18 , and thus the transport load  66  applied to the engine  14  via said transmission, in response to changes in the speed of the engine  14 , with the adjustments in the transmission setting changing the engine  14  load according to a pulse characteristic based upon an operator decided factor. The factor is put into the controller by the operator through a calibration process. This enables the operator to select the reactivity speed which will determine the response rate of the harvester. A higher factor number enables a faster reaction rate to forces acting on the two harvester loads, transport load  66  and crop load  70 . The system does not differentiate between the loads but rather reacts to the combination of both loads. The reaction thus causes the linear actuator  56  to adjust the flow of the hydrostat pump  68  to the transmission increasing or decreasing the transport speed in accordance with the appropriate action required. 
         [0047]    In the particular embodiment illustrated in  FIG. 2 , the transmission control system includes an electro linear actuator  56  having an output member which is connected to the transmission control lever through a mechanical linkage. Movement of the output member of the actuator is proportional to the magnitude of a DC electrical signal supplied to the actuator from an electronic control unit determined by the operator programmable factor. 
         [0048]    In the preferred embodiment of the invention, the proportional actuator is an electro linear actuator  56  that converts electrical pulses supplied by the control box  54  to corresponding mechanical displacement in the position of an output shaft. To the magnitude of the electrical signal which energizes the linear actuators internal motor winding causing the motor to turn and drive a gear that changes the position of the actuators shaft in a linear and incremental motion. 
         [0049]    Input information is supplied by the engine RPM sensor  60  and the transmission speed sensor  58 . Power from the control box  54  passes through the clutch switch  62  before arriving at the linear actuator  56   
         [0050]    Referring to  FIG. 3  in a preferred embodiment of the present invention the invention consists of a control box  54  equipped with a processor, memory, display  106  and operator controls. The control box  54  is programmable and calibrateable. A wire harness  64  with branches to pick up signals from the engine RPM sensor  60 , transmission speed sensor  58  and linear actuator potentiometer  74 . An electro mechanical linear actuator  56  equipped with a linear actuator clutch  76  and potentiometer. 
         [0051]    The control box  54  being equipped with the ability to calibrate the hydrostat neutral position  78 , hydrostat full forward position  80 , engine RPM  82 , and ground speed  92 . 
         [0052]    Operator selectable settings for target engine RPM  84 , maximum engine RPM  86 , minimum engine RPM  88 , slug prevention  90  RPM, maximum ground speed  94 , minimum ground speed  96 , pulses per second  98 , pulse length  100 , slug pulses  102  and slug pulse length  104 . 
         [0053]    In the preferred embodiment of this present invention the combined inputs, calibrations and operator settings permit the present invention to effect the hydrostat pump  68  controlling the hydrostat transmission and ultimately the ground wheels  16  increasing or decreasing their rotational speed to influence engine  14  load and RPM&#39;s. 
         [0054]    Referring now to  FIG. 4 , in a preferred embodiment of the present invention a controller is powered by the harvesters DC electrical power source  128  contains a processor to detect signals from the harvester and uses those signals in conjunction with operator input settings and its internal program to effect the operation of the harvester to the benefit of the operator. The controller is equipped with a display  106 , on/off switch  114 , motor fuse  108 , clutch fuse  110 , indicator lights for running, calibration, clutch and fault, operator input buttons for run button  116 , calibrate button  118 , set button  112 , select up button  120  and select down button  122  for movement in the menu. 
         [0055]    In the preferred embodiment the controller contains a processor of the HC6812 family. The processor is equipped with a memory for retaining the calibration and user selected settings. Information is then processed and signals are sent to the linear actuator  56  to effect a change on the forward speed of the harvester to maintain the proper operating parameters selected by the operator. Information on the harvester&#39;s current operating parameters is gained from the engine RPM sensor  60 , transmission speed sensor  58  and the linear actuator potentiometer  74  through the present inventions wire harness  64 . This information is analyzed and the processor determines if that information is within the operator selected parameters. If the signals indicate the harvester is operating within selected parameters then no effect takes place, if the signals received are not within the parameters selected for the harvester, then an effect takes place. 
         [0056]    If the signals received are out of the range of parameters selected the controller engages a relay that will power the actuator causing the linear actuator shaft  124  to move in one direction or the other to cause the desired reaction. The power from the controller passes by means of the controller wire harness  64  through the clutch switch  62 . The clutch switch  62  in a preferred embodiment is attached to the hydrostat handle  52  where an operator is employed to operate the harvester and the clutch switch  62  is attached to a remote control device where a robotic or remote control is used. The clutch switch  62  interrupts power to the actuator clutch allowing it to freewheel. The freewheeling clutch permits the operator to instantly take manual control of the hydrostat handle  52  overriding the automatic control provided by the present invention. 
         [0057]    The linear actuator  56  moves the hydrostatic pump flow control from a neutral position to a forward position and from a forward position to a neutral position with infinite increments in either direction. When the hydrostat pump  68  flow control is opened, fluid flows to the transmission by means of hydraulic plumbing  126  causing the drive wheels  16  to move the harvester. 
         [0058]    It is understood that this preferred embodiment does not cover all descriptions of all fluid drive systems that the present invention is applicable too but will operate. 
         [0059]    Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention. 
         [0060]    Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims.