Abstract:
A method and apparatus for controlling the flotation system of an agricultural harvesting machine such as a windrower, wherein the system is programmed to be automatically operable for entering a header remove mode when operating conditions indicate an intent to remove the header, which conditions can be, for instance, the setting or a flotation force value for the system to zero or near zero, and which will automatically exit the header remove mode when conditions indicate an intent to return to normal operation, for instance, when a flotation force is increased to at least a predetermined value.

Description:
[0001]     This application claims the benefit of U.S. Provisional Application Nos. 60/699,271, filed Jul. 14, 2005, and 60/699,550, filed Jul. 15, 2005. 
     
    
     TECHNICAL FIELD  
       [0002]     The present invention relates to agricultural windrowers and, more particularly, to a method embodied in a software program and apparatus for controlling the hydraulics during the removal of a windrower header.  
       BACKGROUND OF THE INVENTION  
       [0003]     U.S. Pat. No. 6,901,729, is incorporated herein by reference in its entirety. This patent describes a header flotation system that is referred to as “non-independent”. U.S. Provisional Application Nos. 60/699,271, filed Jul. 14, 2005, and 60/699,550, filed Jul. 15, 2005, are also incorporated herein by reference in their entirety.  
         [0004]     It is the non-independent embodiment that provides the best example of the type of system with which the program of the instant invention can/should be used.  
         [0005]     The present invention relates generally to harvesting machines of the type that require flotation systems for permitting their headers to ride lightly up and over rises in the terrain during field operation, and particularly to a hydraulic header lift and flotation system for such a machine that will provide the dual functions of header lift and flotation.  
         [0006]     Header flotation systems typically use extension springs, either hydraulically or manually adjusted, bell cranks and other linkages to provide the desired function. The structure generally requires numerous components and large extension springs, and it is quite difficult to develop the mechanical components required to float the broad range of header sizes available even requiring different tractors or frames having their own flotation systems designed to meet their own particular header weight requirements.  
         [0007]     Some manufacturers are using an accumulator and hydraulic cylinders to perform the flotation function. These machines typically use separate hydraulic cylinders for the lift and flotation functions, and they lack the capability of independently adjusting the flotation force for each side of the header. Additionally, some headers are not inherently balanced side to side. Special considerations must be made to float and lift these headers evenly by adding ballast, which can become unreasonably heavy or awkward, or modifying the lift geometry of one side.  
         [0008]     It would be quite beneficial to have a header lift and flotation system that employs a single hydraulic cylinder for each side of the header, simplifying the controls and mechanical components necessary to perform these functions.  
         [0009]     It would also be beneficial to have a header lift and flotation system automatically operable for entering a header remove mode when operating conditions indicate an intent to remove the header, and automatically exiting the header remove mode when conditions indicate an intent to return to normal operation.  
       SUMMARY OF THE DISCLOSURE  
       [0010]     Accordingly, it is an object of the present invention is to provide a hydraulic lift and flotation system for the header of a crop harvesting machine that employs a single hydraulic cylinder for each side of the header.  
         [0011]     Another object of the present invention is to provide a hydraulic lift and flotation system to be used with both heavy and light headers/conditioners, i.e., a broad range of header sizes and weights.  
         [0012]     It is another object of the instant invention to provide a more simplified structure that presents greater flexibility in locating the accumulator as opposed to extension springs and necessary linkages, with fewer pivot points to wear and fewer parts to manufacture and assemble.  
         [0013]     It is still another object of the instant invention to provide a flotation and lift system that requires no dealer or customer assembly.  
         [0014]     It is an even still further object of the instant invention to provide a hydraulic header flotation and lift system that reduces hydraulic and mechanical shock loading when raising the header in a less than fully raised position, improving the ride comfort for the operator and improving hydraulic and structural durability of the harvester.  
         [0015]     It is yet another object of this invention to provide an improved hydraulic header lift and flotation system that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple and effective in use.  
         [0016]     It is still another object of the invention to provide a header lift and flotation system automatically operable for entering a header remove mode when operating conditions indicate an intent to remove the header, and automatically exiting the header remove mode when conditions indicate an intent to return to normal operation.  
         [0017]     These and other objects are attained by providing a hydraulic lift/flotation system for the header of a crop harvesting machine. Each side of the header is supported by a single cylinder that performs both the flotation and lift functions. To accommodate unbalanced headers (center of gravity not centered between the lift arms), hydraulic oil is sent to the return side of the lift cylinder on the lighter side of the header, thus resulting in even raising, lowering and float. Additionally, the system is programmed to be automatically operable for entering a header remove mode when operating conditions indicate an intent to remove the header, and automatically exiting the header remove mode when conditions indicate an intent to return to normal operation. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]     The advantages of this invention will be apparent upon consideration of the following detailed disclosure of the invention, especially when taken in conjunction with the accompanying drawings wherein:  
         [0019]      FIG. 1  is a partial side elevational view of a crop harvesting machine of the type with which the invention may be used, also showing a simplified side view of the lift and flotation system of the instant invention; and  
         [0020]      FIG. 2  is a hydraulic schematic view of one embodiment of the hydraulic system of the instant invention;  
         [0021]      FIG. 3  is a schematic of the hydraulic, mechanical and electrical sub-systems that cooperate to produce the system of  FIGS. 1 and 2 ;  
         [0022]      FIG. 4  is a high level flow diagram of steps of a preferred embodiment of a computer program of the invention;  
         [0023]      FIG. 4   a  is a continuation of the diagram of  FIG. 4 ;  
         [0024]      FIG. 5  is a written listing of steps of the preferred program of the invention;  
         [0025]      FIG. 6  is a written listing of further steps of the preferred program of the invention;  
         [0026]      FIG. 7  is a written listing of further steps of the preferred program of the invention;  
         [0027]      FIG. 8  is a written listing of still further steps of the preferred program of the invention;  
         [0028]      FIG. 9  is a written listing of still further steps of the preferred program of the invention;  
         [0029]      FIG. 10  is a written listing of still further steps of the preferred program of the invention;  
         [0030]      FIG. 11  is a written listing of still further steps of the preferred program of the invention;  
         [0031]      FIG. 12  is a written listing of still further steps of the preferred program of the invention;  
         [0032]      FIG. 13  is a written listing of still further steps of the preferred program of the invention;  
         [0033]      FIG. 14  is a written listing of still further steps of the preferred program of the invention;  
         [0034]      FIG. 15  is a written listing of still further steps of the preferred program of the invention;  
         [0035]      FIG. 16  is a written listing of still further steps of the preferred program of the invention;  
         [0036]      FIG. 17  is a written listing of still further steps of the preferred program of the invention;  
         [0037]      FIG. 18  is a written listing of still further steps of the preferred program of the invention;  
         [0038]      FIG. 19  is a written listing of still further steps of the preferred program of the invention;  
         [0039]      FIG. 20  is a written listing of still further steps of the preferred program of the invention;  
         [0040]      FIG. 21  is a written listing of still further steps of the preferred program of the invention;  
         [0041]      FIG. 22  is a written listing of still further steps of the preferred program of the invention;  
         [0042]      FIG. 23  is a written listing of still further steps of the preferred program of the invention;  
         [0043]      FIG. 24  is a written listing of still further steps of the preferred program of the invention;  
         [0044]      FIG. 25  is a written listing of still further steps of the preferred program of the invention;  
         [0045]      FIG. 26  is a written listing of still further steps of the preferred program of the invention;  
         [0046]      FIG. 27  is a written listing of still further steps of the preferred program of the invention;  
         [0047]      FIG. 28  is a written listing of still further steps of the preferred program of the invention;  
         [0048]      FIG. 29  is a written listing of still further steps of the preferred program of the invention;  
         [0049]      FIG. 30  is a written listing of still further steps of the preferred program of the invention; and  
         [0050]      FIG. 31  is a written listing of still further steps of the preferred program of the invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0051]     Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail.  
         [0052]      FIG. 1  shows the present invention utilized in connection with a self-propelled windrower  10 ; however, it will be appreciated that the principles of the present invention are not limited to a self-propelled windrower, or to any specific type of harvesting machine.  
         [0053]     In the illustrated embodiment, the self-propelled windrower  10  comprises a tractor  12  and a header  14 , the header  14  being attached to the front end of the frame  16  or chassis of the tractor  12 . The header may be of generally any suitable construction and design, and may include not only crop-harvesting mechanisms, but also crop conditioners such as elongate rolls  15 . Such attachment of the header  14  to the frame  16  is achieved through a pair of lower arms  18  (only the left one being shown, the right being generally the same) pivoted at one end to the frame  16  and at the other end to the header  14 , as well as through a central upper link  20 . The link  20  may take the form of a single double-acting hydraulic cylinder  21  whose extension and retraction is controlled by the operator to remotely control the angle of sickle bar  22  on the lower front of the header  14 .  
         [0054]     A single lift/flotation cylinder  24 , interconnecting the lower arm  18  and the frame  16  supports each side of the header, i.e., each side of the header is supported by its own lift/flotation cylinder (again, only the left one being shown in this  FIG. 1 ).  
         [0055]     More specifically, the control system accomplishes two generally separate control functions, one for the right side lift/flotation cylinder and one for the left.  
         [0056]     Directing attention now to  FIG. 2 , the hydraulic control system for left cylinder  24  and a right cylinder  26  can be seen to include an electro-hydraulic subsystem generally depicted as  30 . For convenience of assembly and operation, the majority of the components are housed in a single valve body  34  with appropriately located ports and other necessary connection devices and fixtures. A fixed displacement pump  36  moves the hydraulic fluid into subsystem  30  from reservoir  40 , through the various circuits as directed by control valves, to a single accumulator  42 , to hydraulic cylinders  24 ,  26  and back to reservoir  40  as appropriate.  
         [0057]      FIG. 3  provides a more detailed depiction of the complete control system and subsystems. The hydraulic system, as shown also in  FIG. 2 , additionally depicts the electrical control and mechanical subsystems. Importantly, this figure depicts the multi-channel programmable controller  50  which exchanges electrical signals from the float switch  52  (also referred to in the written program code of the invention as trim switch), the PWM (pulse width modulated) solenoid  56  of the proportional pressure reducing valve (PPRV) or (PRV)  58 , the unload/relief valve  60 , and other valves to manage the lift and flotation functions as established by the operator through the appropriate switch and shown on display  64 .  
         [0058]     The hydraulic cylinders, attached to respective ends of the header, perform both the lift and flotation functions. The lifting and floating function is achieved by coupling the lifting end of the hydraulic cylinders to each other and then to a hydraulic pump, control manifold, and accumulator. The operator sets the desired flotation force by actuating the float switch  52 , located on the operator&#39;s console. The set points can range from zero or near zero, to a range of values greater than zero or near zero. One switch position allows hydraulic oil to enter the accumulator (increasing the hydraulic pressure), which reduces the header contact force, or flotation force, with the ground. The other switch position allows oil to exit the accumulator (reducing the hydraulic pressure), which increases the header contact force with the ground. Once the flotation force is set, the controller  50  will normally cause the control valves to return to this preset flotation condition whenever the float mode is selected, irrespective of subsequent header lift and lower movements. To accommodate unbalanced headers (the header center of gravity is not centered between the lift arms), hydraulic oil is applied to the return side of the lift cylinder on the lighter side of the header. The addition of a defined hydraulic pressure on the back side of the cylinder results in the same lifting pressure to be required for each side. The header will then raise, lower, and float evenly. The result is the same as changing the lift geometry or adding ballast to the header. This function is referred to as the “hydraulic counterweight”.  
         [0059]     The hydraulic oil is supplied from the hydraulic ground drive charge pump, which provides constant pressure any time the engine is running. To prevent cavitation of the charge pump during rapid changes in system volume, such as during the header lower cycle, makeup oil is supplied from the header lift pump. The operator sets the hydraulic counterweight by turning a manual control valve  66  to apply more weight (hydraulic pressure) to the light side of the header until the header raises and lowers to a level condition. If too much weight is applied, the operator simply turns the valve in the opposite direction. Once the correct setting is established, the hydraulic counterweight will not need to be readjusted during machine operation. Re-adjustment will only become necessary if the header builds up with debris or upon exchange with another header.  
         [0060]     For headers that experience severe changes in balance during normal operation, i.e., draper headers with deck-shift, an electro-hydraulic valve can be installed in place of the manual control valve. This electro-hydraulic valve is adjusted from a rocker switch on the operator&#39;s console. The operator then sets the hydraulic counterweight for each deck position. Once these values are established, the control valve will adjust automatically as the deck positions are selected.  
         [0061]     In the present example of the windrower  10  and system  30 , they are configured such that the lighter side of header  14  is supported by cylinder  26 , and a hydraulic counterweight can be is applied to cylinder  26  using pressure reducing valve  66  ( FIGS. 2 and 3 ) or an optional electro-hydraulic valve, as just mentioned. During normal operation, either of these arrangements can be used to maintain header  14  level.  
         [0062]     From time to time, it will be desirable to remove header  14  from windrower  10 . This typically entails raising the header using cylinders  24  and  26 . Jack stands, either included on and pivotable downward from header  14 , or separate therefrom, or other support structure for supporting header  14  independently of lower arms  18 , are then deployed. Pins connecting header  14  with lower arms  18  are then removed. Lower arms  18  can now be lowered and separated from header  14 , and upper link  20  disconnected, to enable driving windrower  10  separately of and away from header  14 . Since any flotation force would be outwardly acting on cylinders  24  and  26 , the presence of such flotation force is typically viewed as a detriment when it is desired to disconnect lower arms  18  from header  14 . Lower arms  18  are typically cooperatively received in cups on header  14  and often require some exertion of downward force to release from the cups. Sometimes, the operator will exit the operator cab of windrower  10  and apply his or her weight to lower arms  18  to release them from header  14 . Any upward force, such as a flotation force, would counter this, and thus be undesirable. As result, the operator typically will adjust or set the flotation force using float switch  52  down to zero or near zero. Then, when arms  18  are lowered using a header lower command to operate cylinders  24  and  26 , because there is no upwardly directed flotation force, arms  18  will typically drop or fall from header  14 . With header  14  removed, it may be desirable to raise arms  18 , which can be accomplished by a header raise command to operate cylinders  24  and  26 . However, from a raised position, it will typically be undesirable to execute a header lower command to lower arms  18  without some flotation force present, as arms  18  will essentially just drop. Therefore, it is desirable to have an automatic routine for operation of controller  50  which accommodates operation of system  30  in a header remove mode.  
         [0063]     Directing attention to  FIGS. 4 and 4   a,  a high-level flow diagram  70  illustrating steps of a preferred embodiment of a computer program incorporating a method of the invention for operating controller  50  and system  30  in a header remove mode, is shown.  FIGS. 5 through 31  illustrate steps of the preferred program of the instant invention (see generally lines  540 - 1036 ). The notes on the program provide a very good explanation of the various line items and steps making up the program.  
         [0064]     This program can be used with existing system as shown in U.S. Pat. No. 6,901,729 (non-independent embodiment), and also with an independent system such as disclosed in co-pending U.S. patent application Ser. No. 10/822,465, entitled Independent Hydraulic Header Lift and Flotation System, filed Apr. 12, 2004, both of which are incorporated herein by reference in their entirety. Four cylinder CNH windrowers do not have independent flotation systems, so they do not have the left side flotation components. In this invention, the available left side components are used to operate the counterbalance. In machine  10 , down pressure is applied to the lighter side lift cylinder. The same basic control principle can be applied to PRV  58  to allow it to be used in a manner that supports the identified U.S. patent. In the program, PWM means pulse width modulation, and is expressed as a percentage.  
         [0065]     Directing attention to the program listing of  FIGS. 16 through 24  (lines  540 - 855 ), and also continuing as denoted by balloon A from flow diagram  70  of  FIGS. 4 and 4   a,  steps for operation in a header remove mode are shown. This mode is initiated by float switches  52  and  54  having been operated to drop the set point for the flotation force to zero, or near or about zero, as denoted by decision block  64 . That is, a flotation force level which substantially ineffective for flotation purposes. This is because it is believed that the operator will typically not zero switches  52  and  54  unless it is desired to remove the header. When controller  50  recognizes or initiates the header remove mode, as denoted at block  68 , it will naturally determine at decision block  72  that the trim switch set points are lower than 100 and will set the flotation force to zero (line  546 ) and clear or reset a 5 minute timer (line  567 ), as denoted at blocks  76  and  78 . If a header raise command is present, as determined at decision block  80 , controller  50  will set a flag (line  571 ), and will proceed to execute the command in due course (lines  782 - 820 ) by actuating valves  78  and  80  via solenoids D and H to raise arms  18 , as denoted at block  82 . This is done without first requiring charging the accumulators. Controller  50  will then remain in the header remove mode and return to decision block  80 . If, at decision block  80 , no header raise command is present, controller  50  will proceed, as denoted by following balloon D, to check for the presence of a header lower command, as denoted at decision block  84  in  FIG. 4   a.  If no header lower command is present, following balloon E, controller  50  will remain in the header remove mode (PRVs at zero pressure such that flotation force equals zero), or go to some other suitable location such as to decision block  80 . If, on the other hand, at decision block  84 , a header lower command is detected, controller  50  will output a signal to the operator for a confirmation from the operator that a header lower command is desired (lines  580 - 585 ), as denoted at decision block  86 . This required confirmation can be in the form of a predetermined operator input, such as another push of the header lower switch (line  582 ). If no confirmation is received, e.g., the switch is not pushed, controller  50  will disregard the command and follow balloon E and loop back to the top of the header remove routine, or to another suitable location, such as decision block  80 . If, at decision block  86 , the header lower command is confirmed, controller  50  will proceed to lower the arms, as denoted at block  88 , and check for termination of a header lower command, as denoted at decision block  90 . If the lower command is present the arms will continue to be lowered. If not, the controller will determine if the park brake is off, as denoted at decision block  92 . If yes, it will follow balloon E to the top of the header remove mode. If no, it will continue to lower the arms as denoted at block  94 , and proceed to check if the time is greater than 5 minutes, as denoted at block  96 . If yes, the controller will follow balloon E to the top of the routine. If no, it will loop back to decision block  92 .  
         [0066]     The allotted five minute time is intended to allow the operator time to exit the cab and take necessary steps to disconnect or detach arms  18  from header  14 , such as prying the arms loose from the cups on the header.  
         [0067]     During the normal course of looping through to the top of the header remove routine at balloon E, controller  50  will determine if the trim switch set points are increased to 100 or more, as denoted at decision block  72 , and if yes, controller  50  will exit the header remove mode, as denoted at block  74 . If the set points are not increased to 100, controller  50  will remain looping through this header remove section until the exit condition is met.  
         [0068]     It will be understood that changes in the details, materials, steps and arrangements of parts which have been described and illustrated to explain the nature of the invention will occur to and may be made by those skilled in the art upon a reading of this disclosure within the principles and scope of the invention. The foregoing description illustrates the preferred embodiment of the invention; however, concepts, as based upon the description, may be employed in other embodiments without departing from the scope of the inventions. Accordingly, the following claims are intended to protect the invention broadly as well as in the specific form shown.