Windrower Header Float System with Auxiliary Downforce Control

Abstract

An agricultural machine includes a float cylinder interconnecting a header linkage system and a frame. A rod-side accumulator is in fluid communication with a rod-side fluid port of the float cylinder. A float control valve is selectively controllable between an open position allowing fluid communication between a pressure source and the rod-side accumulator, and a closed position preventing fluid communication between the pressure source and the rod-side accumulator. A downpressure accumulator is in fluid communication with a piston-side fluid port of the float cylinder. The downpressure control valve is selectively controllable between an open position allowing fluid communication between the pressure source and the downpressure accumulator, and a closed position preventing fluid communication between the pressure source and the downpressure accumulator.

Description

Technical Field

[0001] The present disclosure generally relates to an agricultural machine, such as a self-propelled windrower, having a header linkage system operable in a floating operating condition. Background Art

[0002] Some agricultural machines are configured to receive or connect to a cutter head for cutting standing crop material. Such agricultural machines may be referred to as self-propelled windrowers and are typically configured to operate with a variety of different types and / or sizes of cutter heads. Each different size and / or type of cutter head may have different recommended operating settings for the header linkage system that connects the cutter head to the agricultural machine.

[0003] Agricultural machines and attached cutter heads can be configured to cut different crop materials. Crop materials include forage and grain. Because crop materials have different characteristics, the header linkage system and cutter head may need to be positioned differently for different crop materials, or different cutter heads may need to be used for different crop materials.

[0004] Two common types of cutter heads include rotary cutter heads, which are typically used for cutting forage crops, and cutter heads, which are typically used for cutting cereal crops. Each of the rotary and cutter heads can also come in different sizes. Both rotary and cutter heads can operate in either a fixed-height operating mode, in which the position of the header linkage system is fixed relative to the frame of the agricultural machine, maintaining the cutter head at a fixed height above the ground, or a floating operating mode, in which the header linkage system is allowed to move vertically relative to the frame to follow the ground as the agricultural machine travels across it.

[0005] When operating in a floating operating state, it is desirable for the header linkage system to exhibit different operating characteristics for different types of cutter heads (i.e., rotary cutter heads and band cutter heads). For example, because rotary cutter heads can move across the ground more quickly than band cutter heads, it is often desirable to configure the header linkage system to exhibit a fast floating response in order to quickly move the cutter head downward to maintain contact with the ground. In contrast, because band cutter heads use sickle-type cutter bars, they move across the ground more slowly and are more susceptible to mud plugging than rotary cutter heads. Therefore, it is often desirable to configure the header linkage system to exhibit a slow floating response in order to move the band cutter head downward at a more controlled rate so that the sickle-type cutter bar does not dig into the ground. Summary of the Invention

[0006] An agricultural machine is provided. The agricultural machine includes a frame and a header linkage system attached to the frame. The header linkage system is configured to attach a cutter head to the frame. The agricultural machine further includes a container operable to store a supply of fluid and a pressure source in fluid communication with the container. The pressure source is operable to receive fluid from the container and circulate the fluid through a fluid circuit. A floating cylinder interconnects the header linkage system and the frame. The floating cylinder includes a rod-side fluid port and a piston-side fluid port. The rod-side fluid port is in fluid communication with the pressure source. The rod-side fluid port is operable to receive fluid from the pressure source to retract the floating cylinder. A downforce accumulator is in fluid communication with the piston-side fluid port of the floating cylinder. A downforce control valve is in fluid communication with the pressure source and the downforce accumulator. The downforce control valve is selectively controllable between an open position and a closed position. When the downforce control valve is in the open position, it allows fluid communication between the pressure source and the downforce accumulator. When the down pressure control valve is disposed in the closed position, the down pressure control valve blocks fluid communication between the pressure source and the down pressure accumulator.

[0007] In one aspect of the present disclosure, the agricultural machine includes a header controller. The header controller includes a processor and a memory having a header attachment and control algorithm stored therein. The processor is operable to execute the header attachment and control algorithm to control the downforce control valve to the open position or the closed position based on float control requested by an operator. When the downforce control valve is controlled to the open position, the header linkage system can be operated in a first float state exhibiting a first header float return speed. When the downforce control valve is controlled to the closed position, the header linkage system can be operated in a second float state exhibiting a second header float return speed.

[0008] The first header float return speed is less than the second header float return speed. Thus, when operating in the first float state, the header linkage system returns the cutter head to ground contact at a slower rate than when the header linkage system is operating in the second float state. For example, when a band cutter head is connected to the header linkage system, an operator can select to operate the header linkage system in the first float state, thereby causing the band cutter head to slowly return to ground contact at a controlled rate (i.e., the first header float return speed). In contrast, for example, when a rotary cutter head is attached to the header linkage system, an operator can select to operate the header linkage system in the second float state, thereby causing the rotary cutter head to return to ground contact more quickly at a faster rate (i.e., the second header float return speed).

[0009] In one aspect of the present disclosure, the agricultural machine further includes a rod-side accumulator. The rod-side accumulator is in fluid communication with the rod-side fluid port. The rod-side accumulator defines a rod-side space that can be compressed in response to a fluid pressure that is higher than a defined rod-side set point. The rod-side set point can be controlled based on the fluid pressure applied to the rod-side space, thereby defining the resistance against extension of the floating cylinder. The downforce accumulator defines a piston-side space that can be compressed in response to a fluid pressure that is higher than a defined piston-side set point. The piston-side set point can be controlled based on the fluid pressure applied to the piston-side space, thereby defining the resistance against retraction of the floating cylinder. The piston-side set point can be different from the rod-side set point. The rod-side set point and the piston-side set point can be individually controlled by the operator for the specific characteristics of the cutter head attached to the header linkage system, thereby controlling the force required to lift the cutter head and the downward force to return the cutter head to ground contact.

[0010] In one aspect of the present disclosure, an agricultural machine includes a float control valve that is in fluid communication with the pressure source and the rod-side fluid port of the floating cylinder. The float control valve is selectively controllable between an open position and a closed position. When the float control valve is set in the open position, the float control valve allows fluid communication between the pressure source, the rod-side fluid port of the floating cylinder, and the rod-side accumulator. When the float control valve is set in the closed position, the float control valve prevents fluid communication between the pressure source and the rod-side fluid port of the floating cylinder. The float control valve can be opened to control the fluid pressure at the rod-side accumulator and the rod-side volume of the floating cylinder.

[0011] In one aspect of the present disclosure, the rod-side accumulator is disposed within a fluid circuit and between the rod-side fluid port and the float control valve. In another aspect of the present disclosure, the downforce accumulator is disposed within a fluid circuit and between the piston-side fluid port and the downforce control valve.

[0012] In one aspect of the present disclosure, the agricultural machine includes a system return line that interconnects the output of the pressure source with the reservoir in fluid communication. A return valve is in fluid communication with the system return line. The return valve is selectively controllable between an open position and a closed position. When the return valve is in the open position, the return valve allows fluid communication connecting the pressure source to the reservoir through the system return line. When the return valve is in the open position, one or both of the float control valve and / or the downforce control valve can be opened toward the reservoir to allow the rod-side space and / or the piston-side space, respectively, to vent to the reservoir, thereby reducing the fluid pressure in the rod-side space and / or the piston-side space, respectively. When the return valve is in the closed position, the return valve prevents fluid communication through the system return line, thereby providing pressurized fluid to the float control valve and the downforce control valve.

[0013] In one aspect of the present disclosure, the floating cylinder may include a double-acting hydraulic cylinder operable to extend in response to receiving fluid into the piston-side fluid port through the downforce control valve, and operable to retract in response to receiving fluid into the rod-side fluid port through the float control valve.

[0014] In one aspect of the present disclosure, the agricultural machine may be configured as a self-propelled windrower.

[0015] Thus, the agricultural machine described above enables the header linkage system to operate in a floating operating state, with variable levels of downforce control for different types of cutter heads and / or different operating conditions. By opening the downforce control valve, the piston-side space is opened to the reservoir, and the downforce accumulator provides little resistance, causing the header linkage system to return to ground contact more slowly. By closing the downforce control valve, the downforce accumulator acts as a spring, providing a rapid return force, thereby quickly moving the header linkage system back into ground contact.

[0016] The above features and advantages and other features and advantages of the present teachings are readily apparent from the following detailed description of the best modes for carrying out the teachings when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a schematic perspective view of an agricultural machine with a rotary cutter head attached.

[0018] Figure 2 is a schematic perspective view of an agricultural machine with an attached strip cutter head.

[0019] Figure 3 is a schematic diagram of a hydraulic system of an agricultural machine configured in a second floating state.

[0020] Figure 4 is a schematic perspective view of a frame and header linkage system of an agricultural machine.

[0021] Figure 5 is a schematic diagram of a hydraulic system configured in a first floating state.

[0022] Figure 6 is a schematic diagram of an alternative embodiment of a hydraulic system configured in a second floating state. DETAILED DESCRIPTION

[0023] Those skilled in the art will recognize that terms such as "above," "below," "upward," "downward," "top," "bottom," etc., are used in a descriptive manner with respect to the drawings and are not intended to limit the scope of the present disclosure as defined by the appended claims. Furthermore, the teachings described herein may be described in terms of functional and / or logical block components and / or various processing steps. It should be appreciated that such block components may be comprised of any number of hardware, software, and / or firmware components configured to perform the specified functions.

[0024] One of ordinary skill understands that terms of degree such as "substantially," "substantially," or "approximately" refer to a reasonable range outside a given value or orientation, such as approximate tolerances or positional relationships associated with the manufacture, assembly, and use of the described embodiments.

[0025] Referring to the drawings, wherein like numerals represent like parts throughout the several views, Figure 1 and Figure 2 An agricultural machine is generally shown at 20. Figure 1 and Figure 2 The exemplary embodiment of agricultural machine 20 shown in FIG. 1 includes, but is not limited to, a self-propelled windrower. However, it should be understood that the teachings of the present disclosure may be applied to machines other than the exemplary windrower depicted in the figures.

[0026] refer to Figure 1 and Figure 2Agricultural machine 20 includes a frame 22 supporting a prime mover 24. Prime mover 24 may include, but is not limited to, an internal combustion engine, an electric motor, a combination of the two, or some other device capable of generating torque to power agricultural machine 20. A left front drive wheel 26 and a right front drive wheel 28 are each mounted to frame 22 near a front end of frame 22. Left front drive wheel 26 and right front drive wheel 28 are capable of rotating about a transverse axis 30. Transverse axis 30 is generally perpendicular to a longitudinal axis 32 of frame 22.

[0027] As will be appreciated by those skilled in the art, the left front drive wheel 26 and the right front drive wheel 28 can simultaneously rotate about the transverse axis 30 in the same rotational direction and at the same rotational speed to drive the agricultural machine 20 forward or backward, depending on the direction of rotation. Additionally, the left front drive wheel 26 and the right front drive wheel 28 can rotate about the transverse axis 30 in the same rotational direction but at different rotational speeds, or in opposite rotational directions about the transverse axis 30 at the same or different rotational speeds to steer the agricultural machine 20.

[0028] refer to Figure 1 and Figure 2 , the agricultural machine 20 further includes a left rear caster 34 and a right rear caster (not shown) attached to the frame 22. As used herein, the term "caster" should be understood to include a wheel that can rotate a full three hundred and sixty degrees (360°) around a corresponding generally vertical axis. Therefore, each of the left rear caster 34 and the right rear caster can rotate a full three hundred and sixty degrees (360°) around a corresponding generally vertical axis. The left rear caster 34 and the right rear caster can be attached to the frame 22 in a suitable manner. The specific manner in which the left rear caster 34 and the right rear caster are attached to the frame 22 is not relevant to the teachings of the present disclosure, is understood by those skilled in the art, and therefore will not be described in detail herein.

[0029] refer to Figure 3 , the agricultural machine 20 includes a hydraulic system 36. The hydraulic system 36 includes a pressure source 38 that is configured to supply a pressurized fluid flow. The pressure source 38 may include, but is not limited to, a fluid pump coupled to the prime mover 24 in a drivable manner. The pressure source 38 draws fluid from a container 40 and circulates the fluid through a fluid circuit 42. The container 40 receives the fluid from the hydraulic system 36, stores the fluid, and supplies the fluid to the pressure source 38 (e.g., a fluid pump). The fluid flow and / or pressure can be used to operate a variety of different components of the agricultural machine 20, as described in more detail below.

[0030] refer to Figure 4, the agricultural machine 20 includes a header linkage system 44 attached to the frame 22. In the embodiment shown in the drawings and described herein, the header linkage system 44 is attached to the frame 22 near the front end of the frame 22. The header linkage system 44 is configured for attaching a cutter head 46 selected from a plurality of different cutter heads 46 to the frame 22. The plurality of different cutter heads 46 may include, for example, Figure 1 The rotary cutter 48 shown in Figure 2 It should be understood that the plurality of different cutter heads 46 may further include each of the rotary cutter 48 and the draper cutter 50 of different sizes.

[0031] Fluid circuit 42 is configured for operating header linkage system 44 in a floating operating state and a fixed-height operating state. When fluid circuit 42 is configured for operating header linkage system 44 in the floating operating state, header linkage system 44 is permitted to move vertically relative to frame 22 as agricultural machine 20 moves across the ground so that the cutter head can track or follow vertical undulations and variations in the ground.

[0032] refer to Figure 3 and Figure 4 The header linkage system 44 includes a rocker shaft 54 rotatably mounted to the frame 22 for rotational movement about an axis 56 extending transverse to the longitudinal axis 32 of the frame 22. A lift cylinder 58 is attached to and interconnects the rocker shaft 54 and the frame 22. The lift cylinder 58 is operable to rotate the rocker shaft 54 about the axis 56 to raise and lower the selected cutter head 46 relative to the ground. Thus, the lift cylinder 58 is operated to control the vertical height of the selected cutter head 46 above the ground. In the exemplary embodiment described herein, the lift cylinder 58 is a single-acting hydraulic cylinder in fluid communication with the hydraulic system 36. A lift control valve 60 controls fluid communication between the lift cylinder 58 and the pressure source 38. In other embodiments, the lift cylinder 58 may include a double-acting hydraulic cylinder, an electrically actuated linear actuator, or some other device capable of extending and retracting. The lift cylinders 58 extend in the usual manner in response to fluid pressure and / or fluid flow from the hydraulic system 36 and retract by the force of gravity acting on the header linkage system 44 and / or the selected cutter head 46 attached thereto, as understood by those skilled in the art.

[0033] The header linkage system 44 may further include a tilt or tilt cylinder 62. The tilt or tilt cylinder 62 is attached to the frame 22 and the selected cutter head 46 attached to the header linkage system 44, interconnecting the frame 22 and the cutter head 46. The tilt or tilt cylinder 62 is operable to rotate the selected cutter head 46 attached to the header linkage system 44 relative to the ground. More specifically, the tilt or tilt cylinder 62 rotates the selected cutter head 46 about a tilt axis 64 that extends transversely to the longitudinal axis 32 of the frame 22 and through the distal ends of the left and right connecting arms 66 and 68. In the exemplary embodiment described herein, the tilt or tilt cylinder 62 is a double-acting hydraulic cylinder in fluid communication with the hydraulic system 36. In other embodiments, the tilt or tilt cylinder 62 may include a single-acting hydraulic cylinder, an electrically actuated linear actuator, or some other device capable of extending and retracting. The tilt or pan cylinders 62 extend and retract in response to fluid pressure and / or fluid flow from the hydraulic system 36 in a conventional manner as understood by those skilled in the art.

[0034] The header linkage system 44 includes the aforementioned left and right link arms 66, 68. The left link arm 66 is rotatably attached to the frame 22 on the left side of the frame 22, below the rocker shaft 54. A left link 70 is attached to and interconnects the left link arm 66 and the rocker shaft 54. A left float cylinder 72 is attached to and interconnects the frame 22 and the left link 70. The respective front ends of the left float cylinder 72 are attached to the left link 70. The left float cylinder 72 extends rearwardly and vertically upward to the respective rear ends of the left float cylinder 72, which are attached to the frame 22.

[0035] The right connecting arm 68 is rotatably attached to the frame 22 on the right side of the frame 22, below the rocker shaft 54. A right connecting rod 74 is attached to and interconnects the right connecting arm 68 and the rocker shaft 54. A right floating cylinder 76 is attached to and interconnects the frame 22 and the right connecting rod 74. The respective front ends of the right floating cylinder 76 are attached to the right connecting rod 74. The right floating cylinder 76 extends rearward and vertically upward to the respective rear ends of the right floating cylinder 76, which are attached to the frame 22.

[0036] In the exemplary embodiment shown in the accompanying drawings and described herein, the left floating cylinder 72 is a double-acting hydraulic cylinder. As will be understood by those skilled in the art, the left floating cylinder 72 includes a housing defining an interior space. A piston is disposed within the interior space of the housing. A rod is attached to the piston, which is located within the interior space of the housing, and extends to a distal end located outside the housing. The piston and rod are slidably movable relative to the housing within the interior space, thereby varying the length of the left floating cylinder 72. The left floating cylinder 72 includes a rod-side fluid port 78 and a piston-side fluid port 80. The rod-side fluid port 78 of the left floating cylinder 72 is in fluid communication with the pressure source 38 and can receive fluid from the pressure source 38 to retract the left floating cylinder 72. The piston-side fluid port 80 of the left floating cylinder 72 is in fluid communication with the pressure source 38 and can receive fluid from the pressure source 38 to extend the left floating cylinder 72.

[0037] The left float control valve 82 is in fluid communication with and interconnects the pressure source 38 and the rod-side fluid port 78 of the left float cylinder 72. The left float control valve 82 is positioned in fluid communication between the left float cylinder 72 and the pressure source 38. The left float control valve 82 is selectively controllable between an open position and a closed position. When the left float control valve 82 is in the open position, the left float control valve 82 allows fluid communication between the pressure source 38 and the rod-side fluid port 78 of the left float cylinder 72. The fluid circuit 42 can be controlled so that the left float cylinder 72 is operable to retract in response to receiving fluid into the rod-side fluid port 78 of the left float cylinder 72 through the left float control valve 82. Furthermore, when the left float control valve 82 is in the open position, the fluid circuit 42 can be controlled to allow fluid communication between the rod-side fluid port 78 of the left float cylinder 72 and the reservoir 40. When the left float control valve 82 is disposed in the closed position, the left float control valve 82 blocks or prevents fluid communication or flow between the pressure source 38 and the rod-side fluid port 78 of the left float cylinder 72 .

[0038] The left rod-side accumulator 84 is in fluid communication with the rod-side fluid port 78 of the left floating cylinder 72. The left rod-side accumulator 84 is positioned within the fluid circuit 42 in fluid communication with the rod-side fluid port 78 of the left floating cylinder 72 and the left floating control valve 82, and / or in fluid communication between the rod-side fluid port 78 of the left floating cylinder 72 and the left floating control valve 82. As understood by those skilled in the art and as used herein, an accumulator is a pressure vessel that holds a compressible gas and a hydraulic fluid separated by a flexible membrane or piston. The compressible gas is precharged to a predetermined pressure. Hydraulic fluid introduced into the accumulator compresses the compressible gas until the pressure of the compressible gas matches the pressure of the hydraulic fluid. When the pressure of the hydraulic fluid drops below the pressure of the compressible gas, the compressible gas can force the hydraulic fluid out of the accumulator. For example, the accumulator can serve as an energy storage device and / or a spring device in the fluid circuit 42.

[0039] The left floating cylinder 72 is in fluid communication with a left rod-side accumulator 84. The left rod-side accumulator 84 defines a left rod-side volume 86 that is compressible in response to a fluid pressure exceeding a defined left rod-side set point. The fluid pressure within the left rod-side volume 86 defined by the left rod-side accumulator 84 can be controlled to provide resistance to extension of the left floating cylinder 72, as well as to provide a spring effect or spring rate that dampens or resists extension of the left floating cylinder 72. A left rod-side pressure sensor 88 can be included for sensing and monitoring the fluid pressure applied to the rod-side fluid port 78 of the left floating cylinder 72 and the left rod-side accumulator 84.

[0040] In the exemplary embodiment shown in the accompanying drawings and described herein, the right floating cylinder 76 is a double-acting hydraulic cylinder. As will be understood by those skilled in the art, the right floating cylinder 76 includes a housing defining an interior space. A piston is disposed within the interior space of the housing. A rod is attached to the piston within the interior space of the housing and extends to a distal end located outside the housing. The piston and rod are slidably movable relative to the housing within the interior space. The right floating cylinder 76 includes a rod-side fluid port 90 and a piston-side fluid port 92. The rod-side fluid port 90 of the right floating cylinder 76 is in fluid communication with the pressure source 38 and can receive fluid from the pressure source 38 to retract the right floating cylinder 76. The piston-side fluid port 92 of the right floating cylinder 76 is in fluid communication with the pressure source 38 and can receive fluid from the pressure source 38 to extend the right floating cylinder 76.

[0041] The right float control valve 94 is in fluid communication with the pressure source 38 and the rod-side fluid port 90 of the right float cylinder 76, and interconnects the pressure source 38 with the rod-side fluid port 90 of the right float cylinder 76. The right float control valve 94 is positioned in fluid communication between the right float cylinder 76 and the pressure source 38. The right float control valve 94 can be selectively controlled between an open position and a closed position. When the right float control valve 94 is in the open position, the right float control valve 94 allows fluid communication between the pressure source 38 and the rod-side fluid port 90 of the right float cylinder 76. The fluid circuit 42 can be controlled so that the right float cylinder 76 is operable to retract in response to receiving fluid into the rod-side fluid port 90 through the right float control valve 94. Furthermore, when the right float control valve 94 is in the open position, the fluid circuit 42 can be controlled to allow fluid communication between the rod-side fluid port 90 of the right float cylinder 76 and the reservoir 40. When the right float control valve 94 is disposed in the closed position, the right float control valve 94 blocks or prevents fluid communication between the pressure source 38 and the rod-side fluid port 90 of the right float cylinder 76 .

[0042] A right rod-side accumulator 96 is in fluid communication with the rod-side fluid port 90 of the right floating cylinder 76. The right rod-side accumulator 96 is positioned within the fluid circuit 42 in fluid communication with the rod-side fluid port 90 of the right floating cylinder 76 and the right floating control valve 94, and / or in fluid communication between the rod-side fluid port 90 of the right floating cylinder 76 and the right floating control valve 94. The right rod-side accumulator 96 defines a right rod-side volume 98 that is compressible in response to a fluid pressure exceeding a defined right rod-side set point. The fluid pressure within the right rod-side volume 98 defined by the right rod-side accumulator 96 can be controlled to provide resistance to extension of the right floating cylinder 76, as well as to provide damping against extension of the right floating cylinder 76 or to provide a spring effect or spring constant against extension of the right floating cylinder 76. A right rod-side pressure sensor 100 can be included for sensing and monitoring the fluid pressure applied to the rod-side fluid port 90 of the right floating cylinder 76 and the right rod-side accumulator 96.

[0043] A down-pressure accumulator 102 is in fluid communication with the piston-side fluid port 80 of the left floating cylinder 72 and the piston-side fluid port 92 of the right floating cylinder 76. A piston-side pressure sensor 104 may be included for sensing and monitoring the fluid pressure applied to the piston-side fluid port 80 of the left floating cylinder 72, the piston-side fluid port 92 of the right floating cylinder 76, and the down-pressure accumulator 102.

[0044] The down pressure control valve 106 is in fluid communication with the pressure source 38 and the down pressure accumulator 102. The down pressure control valve 106 is positioned in fluid communication between the pressure source 38 on one side of the down pressure control valve 106 and the down pressure accumulator 102, the left float cylinder 72, and the right float cylinder 76 on the other side of the down pressure control valve 106. The down pressure control valve 106 is selectively controllable between an open position and a closed position.

[0045] When the lower pressure control valve 106 is set in the open position, the lower pressure control valve 106 allows fluid communication between the pressure source 38 and the piston-side fluid port 92 of the right floating cylinder 76 and the piston-side fluid port 80 of the left floating cylinder 72. The fluid circuit 42 can be controlled so that the left floating cylinder 72 and the right floating cylinder 76 are operable to extend in response to receiving fluid into the piston-side fluid port 92 of the right floating cylinder 76 and the piston-side fluid port 80 of the left floating cylinder 72 through the lower pressure control valve 106. Additionally, when the lower pressure control valve 106 is set in the open position, the fluid circuit 42 can be controlled to allow fluid communication between the piston-side fluid port 92 of the right floating cylinder 76, the piston-side fluid port 80 of the left floating cylinder 72, and the reservoir 40. When the lower pressure control valve 106 is set in the closed position, the lower pressure control valve 106 blocks or prevents fluid communication or flow between the pressure source 38 and the piston-side fluid port 92 of the right floating cylinder 76 and the piston-side fluid port 80 of the left floating cylinder 72.

[0046] The downforce accumulator 102 defines a piston-side volume 108 that can be compressed in response to a fluid pressure exceeding a defined piston-side set point. The fluid pressure within the piston-side volume 108 of the downforce accumulator 102 can be controlled to provide resistance to retraction of the right and left floating cylinders 76, 72, as well as to provide a damping or spring effect against retraction of the right and left floating cylinders 76, 72.

[0047] In the embodiment described herein, the piston-side set point of the piston-side space 108 is different from the left rod-side set point of the left rod-side accumulator 84 or the right rod-side set point of the right rod-side accumulator 96. The piston-side set point, the left rod-side set point, and the right rod-side set point can be calibrated to provide desired operating characteristics for the specific cutter head 46 being used under current field conditions.

[0048] When the downpressure control valve 106 is set to the open position, the fluid circuit 42 can be controlled to operate the header linkage system 44 in a first floating state. When the header linkage system 44 operates in the first floating state, the downpressure accumulator 102 exhibits a first pressure, and the header linkage system 44 exhibits a first header floating return speed in response to the first pressure from the downpressure accumulator 102. When the downpressure control valve 106 is set to the closed position, the fluid circuit 42 can be controlled to operate the header linkage system 44 in a second floating state. When the header linkage system 44 operates in the second floating state, the downpressure accumulator 102 exhibits a second pressure, and the header linkage system 44 exhibits a second header floating return speed in response to the second pressure from the downpressure accumulator 102. In the embodiment described herein, the first pressure and the first header floating return speed of the downpressure accumulator 102 are less than the second pressure and the second header floating return speed of the downpressure accumulator 102.

[0049] The fluid circuit 42 further includes a system return line 110. The system return line 110 interconnects an output 112 of the pressure source 38 with the container 40 in fluid communication. A reflux valve 114 is in fluid communication with the system return line 110. The reflux valve 114 is positioned within the system return line 110 in fluid communication between the pressure source 38 and the container 40. The reflux valve 114 can be selectively controlled between an open position and a closed position. When the reflux valve 114 is in the open position, the reflux valve 114 allows fluid communication or flow through the system return line 110 to the container 40. When the reflux valve 114 is in the closed position, the reflux valve 114 blocks or prevents fluid communication or flow through the system return line 110 to the container 40.

[0050] The fluid circuit 42 may further include a pressure bypass line 116 including a pressure bypass valve 118. The pressure bypass line 116 and the pressure bypass valve 118 are in fluid communication with and disposed between the output 112 of the pressure source 38 and the container 40. In response to the fluid pressure within the fluid circuit 42 exceeding a defined maximum value, the pressure bypass valve 118 may open to connect the output 112 of the pressure source 38 to the container 40.

[0051] The agricultural machine 20 further includes an operator station 120 that houses the control components of the agricultural machine 20. The control components may include, but are not limited to, output devices and input devices. The output devices are operable to convey messages to the operator. The input devices are operable to receive instructions from the operator. In the exemplary embodiment described herein, the input devices and output devices are combined and implemented as a touch screen display 122. Messages can be conveyed to the operator via the touch screen display 122, and the operator can input data by touching the touch screen display 122, as understood by those skilled in the art. It should be understood that the input devices and output devices may differ from the exemplary embodiment described herein and may be separate components or combined components. For example, the output devices may include, but are not limited to, a video-only display, audio speakers, a light board, etc. The input devices may include, but are not limited to, a mouse, a keyboard, a microphone, etc.

[0052] The header controller 124 is configured to communicate with the touch screen display 122, the tilt control valve, the lift control valve 60, the left float control valve 82, the left rod-side pressure sensor 88, the right float control valve 94, the right rod-side pressure sensor 100, the downforce control valve 106, and the piston-side pressure sensor 104. The header controller 124 is operable to receive data input from the left rod-side pressure sensor 88, the right rod-side pressure sensor 100, the piston-side pressure sensor 104, and the touch screen display 122. Additionally, the header controller 124 can send messages through the touch screen display 122 and control the operation of the tilt or tilt cylinder 62, the lift control valve 60, the left float control valve 82, the right float control valve 94, and the downforce control valve 106. While the header controller 124 is generally described herein as a single device, it should be understood that the header controller 124 may include multiple devices linked together to share and / or communicate information between the multiple devices. Furthermore, it should be understood that all or a portion of header controller 124 may be located on or remote from agricultural machine 20 .

[0053] The header controller 124 may alternatively be referred to as a computing device, computer, controller, control unit, control module, module, etc. The header controller 124 includes a processor 126, memory 128, and all software, hardware, algorithms, connections, sensors, etc. required to manage and control the operation of the touch screen display 122, the tilt or swing cylinder 62, the lift control valve 60, the left float control valve 82, the right float control valve 94, and the downforce control valve 106. Thus, the method may be implemented as a program or algorithm capable of operating on the header controller 124. It should be understood that the header controller 124 may include any device capable of analyzing data from a variety of different sensors, comparing the data, making decisions, and performing the required tasks.

[0054] As used herein, "controller" is intended to be consistent with how such term is used by persons skilled in the art and refers to a computing component having processing capabilities, memory capabilities, and communication capabilities that is utilized to execute instructions (i.e., instructions stored on memory or received via communication capabilities) to control or communicate with one or more other components. In certain embodiments, the header controller 124 can be configured to receive input signals in a variety of formats (e.g., hydraulic signals, voltage signals, current signals, CAN messages, optical signals, radio signals) and to output command or communication signals in a variety of formats (e.g., hydraulic signals, voltage signals, current signals, CAN messages, optical signals, radio signals).

[0055] The header controller 124 can communicate with other components on the agricultural machine 20, such as hydraulic components, electrical components, and operator input devices within the operator station 120. The header controller 124 can be electrically connected to these other components via a wiring harness, so that messages, commands, and power can be transmitted between the header controller 124 and the other components. Although the header controller 124 is referenced in the singular, in alternative embodiments, the configuration and functionality described herein can be split across multiple devices using techniques known to those of ordinary skill in the art.

[0056] The header controller 124 can be implemented as one or more digital computers or mainframes, each having one or more processors, read-only memory (ROM), random-access memory (RAM), electrically programmable read-only memory (EPROM), optical drives, magnetic drives, etc., a high-speed clock, analog-to-digital (A / D) circuits, digital-to-analog (D / A) circuits, and any required input / output (I / O) circuits, I / O devices and communication interfaces, and signal conditioning and buffering electronics.

[0057] Computer-readable memory 128 may include any non-transitory / tangible medium that participates in providing data or computer-readable instructions. Memory 128 may be non-volatile or volatile. Non-volatile media may include, for example, optical or magnetic disks and other persistent memory. Example volatile media may include dynamic random access memory (DRAM), which may constitute main memory. Other examples of memory embodiments include floppy disks, soft or hard disks, magnetic tape or other magnetic media, CD-ROMs, DVDs, and / or any other optical media, as well as other possible storage devices, such as flash memory.

[0058] The header controller 124 includes tangible, non-transitory memory 128 having recorded thereon computer-executable instructions, including a header attachment and control algorithm 130. The processor 126 of the header controller 124 is configured to execute the header attachment and control algorithm 130. The header attachment and control algorithm 130 implements a method of controlling the agricultural machine 20.

[0059] The header controller 124 can control the header linkage system 44 for operation between a float operating state and a fixed-height operating state. When the header linkage system 44 is configured for the fixed-height operating state, the position of the header linkage system 44 is fixed relative to the frame 22 of the agricultural machine 20. When the header linkage system 44 is configured for the float operating state, the header linkage system 44 allows the selected cutter head 46 to track or follow the ground vertically during horizontal movement of the agricultural machine 20 over the ground.

[0060] The header controller 124 may receive commands from the operator via the touch screen display 122. The commands may include, but are not limited to, selecting a desired operating state (i.e., a fixed-height operating state or a floating operating state). If the floating operating state is selected, the header controller 124 may further receive commands from the operator to select a desired float state (i.e., a first float state or a second float state). The header controller 124 may then control the return valve 114, the downforce control valve 106, the left float control valve 82, and / or the right float control valve 94 to configure the fluid circuit 42 for the selected float state (i.e., the first float state or the second float state).

[0061] refer to Figure 5 , describes the control of the fluid circuit 42 for controlling the header linkage system 44 in the first floating state. Figure 5 Before the fluid circuit 42 is shown, the header controller 124 can control the return valve 114 to its closed position, and the left and right float control valves 82, 94 can be controlled to their respective open positions to pressurize the left and right rod side spaces 86, 98 to the desired fluid pressure. Once the left and right rod side spaces 86, 98 have reached their respective desired fluid pressures, the header controller 124 can control the left and right float control valves 82, 94 to their respective closed positions. Figure 5As shown, to operate the header linkage system 44 in the first float state, the header controller 124 controls or maintains the left and right float control valves 82, 94 in their respective closed positions, controls the downforce control valve 106 in its open position, and controls the return valve 114 in its open position. This configuration opens fluid communication between the piston-side fluid port 80 of the left float cylinder 72, the piston-side fluid port 92 of the right float cylinder 76, and the downforce accumulator 102 and the reservoir 40 via the return valve 114. When configured in this manner, the downforce accumulator 102 does not provide any significant or effective damping, does not provide a significant or effective spring effect, and / or does not significantly or effectively bias the header linkage system 44 downward. As a result, the header linkage system 44 moves downward relative to the frame 22 at the first header float return speed, which is a slower return speed. The first floating return speed of the header is based at least in part on the weight of the cutter head 46, the fluid pressure in the left rod side space 86 associated with the left rod side set point, and the fluid pressure in the right rod side space 98 associated with the left rod side set point. The operator can select the first floating state when using the band cutter 50, which moves slower on the ground than the rotary cutter 48, thereby allowing more time to return the cutter head 46 to the ground. In addition, the band cutter 50 is more sensitive to contact with the ground. Therefore, it is desirable to control the band cutter 50 more accurately and / or more slowly to ensure that the band cutter 50 does not contact the ground.

[0062] refer to Figure 3 , describes the control of the fluid circuit 42 for controlling the header linkage system 44 in the second floating state. Figure 3 Before the fluid circuit 42 is shown, the header controller 124 can control the return valve 114 to its closed position and control the left float control valve 82 and the right float control valve 94 to their respective open positions to pressurize the left rod side space 86 and the right rod side space 98 to the desired fluid pressure. Once the left rod side space 86 and the right rod side space 98 have reached their respective desired fluid pressures, the header controller 124 can control the left float control valve 82 and the right float control valve 94 to their respective closed positions. In addition, in a configuration such as Figure 3 Before the fluid circuit 42 is shown, the header controller 124 can control the return valve 114 to its closed position and the down pressure control valve 106 to its open position to pressurize the piston side space 108 to the desired fluid pressure. Once the piston side space 108 has reached its desired fluid pressure, the header controller 124 can control the down pressure control valve 106 to its closed position. Figure 3As shown, to operate the header linkage system 44 in the second float state, the header controller 124 controls or maintains the left float control valve 82 and the right float control valve 94 in their respective closed positions. Furthermore, the header controller 124 controls or maintains the downforce control valve 106 in its closed position and controls the return valve 114 in its open position. This configuration closes or prevents fluid communication between the piston-side fluid port 80 of the left float cylinder 72, the piston-side fluid port 92 of the right float cylinder 76, the downforce accumulator 102, and the reservoir 40. Furthermore, this configuration closes or prevents fluid communication between the left rod-side fluid port 78 of the left float cylinder 72 and the left rod-side space 86 and the reservoir 40, as well as between the right rod-side fluid port 90 of the right float cylinder 76 and the right rod-side space 98 and the reservoir 40.

[0063] When configured in this manner, the downforce accumulator 102 provides a significant or effective damping effect, and provides a significant or effective spring effect, and / or biases the header linkage system 44 downward. Consequently, the header linkage system 44 moves downward at a second header float return speed, which is a faster return speed based at least in part on the fluid pressure associated with the piston-side setpoint within the piston-side volume 108, plus the weight of the cutter head 46, the fluid pressure associated with the left rod-side setpoint within the left rod-side volume 86, the fluid pressure associated with the left rod-side setpoint within the right rod-side volume 98, and the fluid pressure associated with the piston-side setpoint within the piston-side volume 108. Thus, the energy stored in the downforce accumulator 102 pushes or biases the cutter head 46 and header linkage system 44 downward to increase the speed at which the cutter head 46 returns to ground contact. The operator may select the second float state when using the rotary cutter 48, which moves faster over the ground than the band cutter 50, thus requiring a faster return response time, and because the rotary cutter 48 is less sensitive to contact with the ground.

[0064] refer to Figure 6 , an alternative embodiment of a hydraulic system is shown generally at 200. Figures 1 to 5 The reference numerals of the features in Figure 6 The same features in Figure 6 The hydraulic system 200 shown in FIG. Figures 3 to 5 The lifting cylinder 58 and the lifting control valve 60 shown in FIG. Figure 6 The hydraulic system 200 shown in FIG. 2 includes a left lift control valve 202 and a right lift control valve 204 .

[0065] The left lift control valve 202 is positioned in fluid communication between the left float control valve 82 and the left rod-side accumulator 84 at a position that does not interrupt or interfere with fluid communication between the left float control valve 82 and the rod-side fluid port 78 of the left float cylinder 72. The left lift control valve 202 controls fluid communication between the left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72. The left lift control valve 202 is movable between an open position, the open position permitting fluid communication between the left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72, and a closed position preventing fluid communication between the left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72. When the left lift control valve 202 is disposed in its open position, thereby permitting fluid communication between the left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72, the left float cylinder 72 and the hydraulic system 200 can be controlled to operate in the first floating state or the second floating state, as described above with reference to FIG. Figure 3 and Figure 5 When the left lift control valve 202 is set in its closed position, thereby preventing fluid communication between the left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72, the left float cylinder 72 and the hydraulic system 200 can be controlled to raise or lower the header linkage system 44, thereby functionally providing lift to the header linkage system 44.

[0066] The right lift control valve 204 is positioned in fluid communication between the right float control valve 94 and the right rod-side accumulator 96 at a position that does not interrupt or interfere with fluid communication between the right float control valve 94 and the rod-side fluid port 90 of the right float cylinder 76. The right lift control valve 204 controls fluid communication between the right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76. The right lift control valve 204 is movable between an open position, the open position permitting fluid communication between the right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76, and a closed position preventing fluid communication between the right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76. When the right lift control valve 204 is disposed in its open position, thereby permitting fluid communication between the right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76, the right float cylinder 76 and the hydraulic system 200 can be controlled to operate in either the first floating state or the second floating state, as described above with reference to FIG. Figure 3 and Figure 5 When the right lift control valve 204 is set to its closed position, thereby preventing fluid communication between the right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76, the right float cylinder 76 and the hydraulic system 200 can be controlled to raise or lower the header linkage system 44, thereby functionally providing lift to the header linkage system 44.

[0067] Therefore, in Figure 6 In the embodiment shown, the left float cylinder 72 and the right float cylinder 76 can provide the floating function as well as Figures 3 to 5 The lift function shown is performed by lift cylinder 58 and lift control valve 60 .

[0068] As used herein, “for example” is used to list examples in a non-exhaustive manner and carries the same meaning as alternative illustrative phrases such as “including,” “including but not limited to,” and “including, without limitation,” etc. As used herein, unless otherwise limited or modified, a list of elements separated by a conjunction (e.g., “and”) and preceded by the phrases “one or more,” “at least one,” “at least,” or similar phrases represents a configuration or arrangement that may include the individual elements in the list or any combination thereof. For example, “at least one of A, B, and C” and “one or more of A, B, and C” respectively represent the following possibilities: only A, only B, only C, or any combination of two or more of A, B, and C (A and B; A and C; B and C; or A, B, and C). As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the,” and “said” are also intended to include the plural forms. In addition, phrases such as “including,” “having,” and similar phrases are intended to specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude or add the presence of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0069] The detailed description and accompanying drawings or figures support and describe the present disclosure, but the scope of the present disclosure is limited only by the claims. Although some of the best modes and other embodiments for carrying out the claimed teachings have been described in detail, there are many alternative designs and embodiments for practicing the disclosure as defined in the appended claims.

Claims

1. A windrower (20), comprising: Frame (22); a header linkage system (44) attached to the frame (22) and configured to attach a cutter head (46) to the frame (22); a container (40) operable to store a supply of fluid; a pressure source (38) in fluid communication with the container (40) and operable to receive fluid from the container (40) and circulate the fluid through a fluid circuit (42); a floating cylinder (72, 76) interconnecting the header linkage system (44) and the frame (22), the floating cylinder (72, 76) including a rod-side fluid port (78, 90) and a piston-side fluid port (80, 92), the rod-side fluid port (78, 90) being in fluid communication with the pressure source (38) for receiving fluid from the pressure source (38) to retract the floating cylinder (72, 76); a down-pressure accumulator (102) in fluid communication with the piston-side fluid ports (80, 92) of the floating cylinders (72, 76); a downforce control valve (106) in fluid communication with the pressure source (38) and the downforce accumulator (102), wherein the downforce control valve (106) is selectively controllable between an open position allowing fluid communication between the pressure source (38) and the downforce accumulator (102) and a closed position preventing fluid communication between the pressure source (38) and the downforce accumulator (102); and A header controller (124) is configured to control the downforce control valve (106) to the open position so that the header linkage system (44) operates in a first floating state exhibiting a first header float return speed, and to control the downforce control valve (106) to the closed position so that the header linkage system (44) operates in a second floating state exhibiting a second header float return speed, wherein the first header float return speed is less than the second header float return speed.

2. The windrower (20) of claim 1 further comprising a rod-side accumulator (84, 96) in fluid communication with the rod-side fluid port (78, 90).

3. The windrower (20) according to claim 2, wherein: The downforce accumulator (102) defines a piston-side space (108) that is compressible in response to a fluid pressure above a defined piston-side set point, and the rod-side accumulators (84, 96) define a rod-side space (86, 98) that is compressible in response to a fluid pressure above a defined rod-side set point, wherein the piston-side set point is different from the rod-side set point.

4. The windrower (20) of claim 2, further comprising a float control valve (82, 94) in fluid communication with the pressure source (38) and the rod-side fluid port (78, 90) of the float cylinder (72, 76), wherein the float control valve (82, 94) is selectively controllable between an open position allowing fluid communication between the pressure source (38) and the rod-side fluid port (78, 90) of the float cylinder (72, 76) and a closed position preventing fluid communication between the pressure source (38) and the rod-side fluid port (78, 90) of the float cylinder (72, 76).

5. The windrower (20) according to claim 4, wherein: The rod-side accumulator (84, 96) is disposed within the fluid circuit (42) between the rod-side fluid port (78, 90) and the float control valve (82, 94).

6. The windrower (20) of claim 1, comprising a system return line (110) fluidly interconnecting an output (112) of the pressure source (38) with the reservoir (40).

7. The windrower (20) of claim 6, further comprising a return valve (114) in fluid communication with the system return line (110), wherein the return valve (114) is selectively controllable between an open position allowing fluid communication through the system return line (110) and a closed position preventing fluid communication through the system return line (110).

8. The windrower (20) of claim 4, wherein: The float cylinders (72, 76) are double-acting hydraulic cylinders operable to extend in response to receiving fluid into the piston-side fluid ports (80, 92) via the downforce control valve (106), and to retract in response to receiving fluid into the rod-side fluid ports (78, 90) via the float control valve (82, 94).

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