Windrower Variable Rate Header Float System

Abstract

An agricultural machine includes a float cylinder interconnecting a header linkage system and a frame of the machine. A first rod-side accumulator and a second rod-side accumulator are both in fluid communication with a rod-side fluid port of the float cylinder. A first accumulator control valve is positioned to control the first rod-side accumulator and is selectively controllable between an open position that allows fluid communication between the first rod-side accumulator and the rod-side fluid port of the float cylinder, and a closed position that prevents fluid communication between the first rod-side accumulator and the rod-side fluid port of the float cylinder. The system provides a first, slower float response when the first accumulator control valve is open, and a second, faster float response when the first accumulator control valve is closed.

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, the header linkage system being attached to the frame. The header linkage system is configured to attach a cutter head to the frame. The agricultural machine includes a fluid circuit comprising a tank operable to store a supply of fluid and a pressure source, the tank being fluidically connected to the tank. The pressure source is operable to receive fluid from the tank and circulate the fluid through the fluid circuit. A floating cylinder interconnects the header linkage system and the frame. The floating cylinder includes a rod-side fluid port fluidically connected to the pressure source. A first rod-side accumulator is fluidically connected to the rod-side fluid port of the floating cylinder. A second rod-side accumulator is fluidically connected to the rod-side fluid port of the floating cylinder. A first accumulator control valve is positioned to control the first rod-side accumulator. The first accumulator control valve is selectively controllable between an open position and a closed position. When the first accumulator control valve is set to the open position, the first accumulator control valve allows fluid communication between the first rod-side accumulator and the rod-side fluid port of the floating cylinder. When the first accumulator control valve is set to the closed position, the first accumulator control valve blocks fluid communication between the first rod-side accumulator and the rod-side fluid port of the floating cylinder.

[0007] In one aspect of the present disclosure, when the first accumulator control valve is set to the open position, the first rod-side accumulator and the second rod-side accumulator jointly apply a first float response to the rod-side fluid port of the float cylinder. When the first accumulator control valve is set to the closed position, only the second rod-side accumulator applies a second float response to the rod-side fluid port of the float cylinder. The first float response is slower than the second float response, such that the first float response moves the header linkage system back to the ground at a slower rate than the second float response. The first float response may be appropriate when a belt header is attached to the header linkage system, while the second float response may be appropriate when a rotary header is attached to the header linkage system.

[0008] In one aspect of the present disclosure, the first rod-side accumulator defines a first volume that is compressible in response to a fluid pressure above a defined first set point, and the second rod-side accumulator defines a second volume that is compressible in response to a fluid pressure above a defined second set point. In one embodiment, the first volume is equal to the second volume. In another embodiment, the first volume is not equal to the second volume. In one embodiment, the defined first set point is equal to the defined second set point. In another embodiment, the defined first set point is not equal to the defined second set point. The first and second volumes, as well as the defined first and second set points, can be designed to provide a desired response for each of the first and second float responses.

[0009] In one aspect of the present disclosure, an agricultural machine includes a float control valve in fluid communication with a pressure source and a rod-side fluid port of a float cylinder. The float control valve is selectively controllable between an open position and a closed position. When the float control valve is in the open position, the float control valve allows fluid communication between the pressure source and the rod-side fluid port of the float cylinder. When the float control valve is in the closed position, the float control valve prevents fluid communication between the pressure source and the rod-side fluid port of the float cylinder.

[0010] In one aspect of the present disclosure, the first rod-side accumulator and the second rod-side accumulator are both positioned in fluid communication within a fluid circuit and between the float cylinder and the float control valve.

[0011] In one aspect of the present disclosure, the float cylinder is a single-acting hydraulic cylinder operable to retract in response to receiving fluid into the rod-side fluid port of the float cylinder and to extend in response to gravity moving the header linkage system.

[0012] In one aspect of the present disclosure, the agricultural machine may further include a second accumulator control valve. The second accumulator control valve is positioned to control the second rod-side accumulator. The second accumulator control valve is selectively controllable between an open position and a closed position. When the second rod-side accumulator is set in the open position, the second rod-side accumulator allows fluid communication between the second rod-side accumulator and the rod-side fluid port of the floating cylinder. When the second rod-side accumulator is set in the closed position, the second rod-side accumulator prevents fluid communication between the second rod-side accumulator and the rod-side fluid port of the floating cylinder.

[0013] In one aspect of the present disclosure, the agricultural machine includes a header controller configured to control the first accumulator control valve. The header controller may control the first accumulator control valve to an open position thereof to operate the header linkage system in a first floating state with a first floating response exhibiting a first header floating return speed. The header controller may control the first accumulator control valve to a closed position thereof to operate the header linkage system in a second floating state with a second floating response exhibiting a second header floating return speed.

[0014] In one embodiment, the header controller may be further configured to simultaneously control the first accumulator control valve to be in its closed position and the second accumulator control valve to be in its closed position when the float control valve is opened, thereby operating the header linkage system in a raised state to raise the header linkage system relative to the frame.

[0015] 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

[0016] Figure 1 is a schematic perspective view of an agricultural machine with a rotary cutter head attached.

[0017] Figure 2 is a schematic perspective view of an agricultural machine with an attached strip cutter head.

[0018] Figure 3 is a schematic diagram of a hydraulic system of an agricultural machine configured in a second floating state.

[0019] Figure 4 is a schematic perspective view of a frame and header linkage system of an agricultural machine.

[0020] Figure 5 is a schematic perspective view of an alternative embodiment of a hydraulic system. DETAILED DESCRIPTION

[0021] 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.

[0022] 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.

[0023] 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.

[0024] refer to Figure 1 and Figure 2 Agricultural 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.

[0025] 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.

[0026] 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.

[0027] 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 tank 40 and circulates the fluid through a fluid circuit 42. The tank 40 receives 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 may be used to operate a variety of different components of the agricultural machine 20, as described in more detail below.

[0028] 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.

[0029] The fluid circuit 42 is configured for operating the header linkage system 44 in a floating operating state and a fixed-height operating state. When the fluid circuit 42 is configured for operating the header linkage system 44 in the floating operating state, the header linkage system 44 is permitted to move vertically relative to the frame 22 as the agricultural machine 20 moves across the ground so that the cutter head 46 can track or follow vertical undulations and variations in the ground.

[0030] refer to Figure 3 and Figure 4The 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] In the exemplary embodiment shown in the drawings and described herein, the left floating cylinder 72 is a single-acting hydraulic cylinder. As will be understood by those skilled in the art, the left floating cylinder 72 includes a housing defining an interior volume or space. A piston is disposed within the interior volume or space of the housing. A rod is attached to the piston, located within the interior volume or space of the housing, and extends to a distal end located outside the housing. The piston and rod can slidably move relative to the housing within the interior volume or 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. As a single-acting hydraulic cylinder, 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 tank 40. Gravity acting on the header linkage system 44 and the cutter head 46 forces the header linkage downward, thereby causing the left floating cylinder 72 to extend.

[0035] 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 tank 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 .

[0036] The first left rod-side accumulator 84 is in fluid communication with the rod-side fluid port 78 of the left floating cylinder 72. The first 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.

[0037] The left floating cylinder 72 is in fluid communication with a first left rod-side accumulator 84. The first left rod-side accumulator 84 defines a first left rod-side volume or space 86 that is compressible in response to a fluid pressure above a defined first left rod-side set point. The fluid pressure within the first left rod-side volume or space 86 defined by the first left rod-side accumulator 84 can be controlled to provide resistance to extension of the left floating cylinder 72, as well as to provide damping against extension of the left floating cylinder 72 or to provide a spring effect or spring rate against extension of the left floating cylinder 72.

[0038] The first left accumulator control valve 140 is positioned to control the first left rod-side accumulator 84. The first left accumulator control valve 140 is selectively controllable between an open position and a closed position. When the first left accumulator control valve 140 is in the open position, the first left accumulator control valve 140 allows fluid communication between the first left rod-side accumulator 84 and the rod-side fluid port 78 of the left floating cylinder 72. When the first left accumulator control valve 140 is in the closed position, the first left accumulator control valve 140 prevents fluid communication between the first left rod-side accumulator 84 and the rod-side fluid port 78 of the left floating cylinder 72.

[0039] The fluid circuit further includes a second left rod-side accumulator 142 in fluid communication with the rod-side fluid port 78 of the left float cylinder 72. The second left rod-side accumulator 142 is positioned within the fluid circuit 42 in fluid communication with the rod-side fluid port 78 of the left float cylinder 72 and the left float control valve 82, and / or in fluid communication between the rod-side fluid port 78 of the left float cylinder 72 and the left float control valve 82. The left float cylinder 72 is in fluid communication with the second left rod-side accumulator 142. The second left rod-side accumulator 142 defines a second left rod-side volume or space 144 that is compressible in response to a fluid pressure above a defined second left rod-side set point. The fluid pressure within the second left rod side volume or space 144 defined by the second left rod side accumulator 142 can be controlled to provide resistance against extension of the left floating cylinder 72 and to provide damping against extension of the left floating cylinder 72 or to provide a spring effect or spring constant against extension of the left floating cylinder 72.

[0040] In one embodiment, the first left rod-side volume or space 86 can be equal to the second left rod-side volume or space 144. However, in other embodiments, the first left rod-side volume or space 86 can be different from, i.e., not equal to, the second left rod-side volume or space 144. Additionally, the defined first left rod-side set point of the first left rod-side accumulator 84 can be equal to the defined second left rod-side set point of the second left rod-side accumulator 142. However, in other embodiments, the defined first left rod-side set point of the first left rod-side accumulator 84 can be different from, i.e., not equal to, the defined second left rod-side set point of the second left rod-side accumulator 142.

[0041] A left rod-side pressure sensor 88 may be included for sensing and monitoring fluid pressure applied to the rod-side fluid port 78 of the left floating cylinder 72 and the first left rod-side accumulator 84 .

[0042] In the exemplary embodiment shown in the drawings and described herein, the right floating cylinder 76 is a single-acting hydraulic cylinder. As will be understood by those skilled in the art, the right floating cylinder 76 includes a housing defining an interior volume or space. A piston is disposed within the interior volume or space of the housing. A rod is attached to the piston within the interior volume or space of the housing and extends to a distal end located outside the housing. The piston and rod can slide relative to the housing within the interior volume or space, thereby varying the length of the right floating cylinder 76. The right floating cylinder 76 includes a rod-side fluid port 90 and a piston-side fluid port 92. As a single-acting hydraulic cylinder, 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 tank 40. Gravity acting on the header linkage system 44 and the cutter head 46 forces the header linkage downward, thereby causing the right floating cylinder 76 to extend.

[0043] 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, interconnecting 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 of the right float cylinder 76 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 tank 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 or flow between the pressure source 38 and the rod-side fluid port 90 of the right float cylinder 76 .

[0044] The first right rod-side accumulator 96 is in fluid communication with the rod-side fluid port 90 of the right floating cylinder 76. The first 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. 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 pre-charged 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 be used as an energy storage device and / or a spring device in the fluid circuit 42.

[0045] The right floating cylinder 76 is in fluid communication with a first right rod-side accumulator 96. The first right rod-side accumulator 96 defines a first right rod-side volume or space 98 that is compressible in response to a fluid pressure above a defined first right rod-side set point. The fluid pressure within the first right rod-side volume or space 98 defined by the first 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.

[0046] The first right accumulator control valve 146 is positioned to control the first right rod-side accumulator 96. The first right accumulator control valve 146 is selectively controllable between an open position and a closed position. When the first right accumulator control valve 146 is in the open position, the first right accumulator control valve 146 allows fluid communication between the first right rod-side accumulator 96 and the rod-side fluid port 90 of the right floating cylinder 76. When the first right accumulator control valve 146 is in the closed position, the first right accumulator control valve 146 prevents fluid communication between the first right rod-side accumulator 96 and the rod-side fluid port 90 of the right floating cylinder 76.

[0047] The fluid circuit further includes a second right rod-side accumulator 148 in fluid communication with the rod-side fluid port 90 of the right floating cylinder 76. The second right rod-side accumulator 148 is positioned within the fluid circuit 42 in fluid communication with and / or between the rod-side fluid port 90 of the right floating cylinder 76 and the right float control valve 94. The right floating cylinder 76 is in fluid communication with the second right rod-side accumulator 148. The second right rod-side accumulator 148 defines a second right rod-side volume or space 150 that is compressible in response to a fluid pressure above a defined second right rod-side set point. Fluid pressure within the second right rod side volume or space 150 defined by the second right rod side accumulator 148 can be controlled to provide resistance against extension of the right floating cylinder 76 and 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 .

[0048] In one embodiment, the first right rod-side volume or space 98 can be equal to the second right rod-side volume or space 150. However, in other embodiments, the first right rod-side volume or space 98 can be different from, i.e., not equal to, the second right rod-side volume or space 150. Additionally, the defined first right rod-side set point of the first right rod-side accumulator 96 can be equal to the defined second right rod-side set point of the second right rod-side accumulator 148. However, in other embodiments, the defined first right rod-side set point of the first right rod-side accumulator 96 can be different from, i.e., not equal to, the defined second right rod-side set point of the second right rod-side accumulator 148.

[0049] A right rod-side pressure sensor 100 may be included for sensing and monitoring fluid pressure applied to the rod-side fluid port 90 of the right floating cylinder 76 and the first right rod-side accumulator 96 .

[0050] 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 tank 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 tank 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 tank 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 tank 40.

[0051] 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 in fluid communication between the output 112 of the pressure source 38 and the tank 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 tank 40.

[0052] 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.

[0053] 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 first left accumulator control valve 140, and the first right accumulator control valve 146. 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, 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, the first left accumulator control valve 140, and the first right accumulator control valve 146. 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 .

[0054] 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, the first left accumulator control valve 140, and the first right accumulator control valve 146. 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.

[0055] 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).

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] The header controller 124 can 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 can 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 can then control the return valve 114, the left float control valve 82, the first left accumulator control valve 140, the right float control valve 94, and / or the first right accumulator control valve 146 to configure the fluid circuit 42 for the selected float state (i.e., the first float state or the second float state).

[0062] When the hydraulic system 36 is configured to provide a first float state, the hydraulic system provides a first float response exhibiting a first header float return speed. When the hydraulic system 36 is configured to provide a second float state, the hydraulic system 36 provides a second float response exhibiting a second header float return speed. The first float response and the first header float return speed are slower than the second float response and the second header float return speed. Thus, when operating the band cutter 50, an operator can select the first float state for the first float response, causing the band cutter 50 to return to the ground at a relatively slower rate than the second float state, while when operating the rotary cutter 48, an operator can select the second float state for the second float response, causing the rotary cutter 48 to return to the ground at a relatively faster rate than the first float state.

[0063] refer to Figure 3 , describes the control of the fluid circuit 42 for controlling the header linkage system 44 in a first float state. The first float state of the hydraulic system 36 includes the left and right float control valves 82, 94 positioned in their respective closed positions. The first left accumulator control valve 140 and the first right accumulator control valve 146 are positioned in their respective open positions. This configuration allows both the first rod-side accumulator 84 and the second left rod-side accumulator 142 to communicate with the rod-side fluid port 78 of the left float cylinder 72. By utilizing both the first and second left rod-side accumulators 84, 142, the first left rod-side volume or space 86 and the second left rod-side volume or space 144 combine to apply the first float response to the rod-side fluid port 78 of the left float cylinder 72. Furthermore, this configuration allows both the first and second right rod-side accumulators 96, 148 to communicate with the rod-side fluid port 90 of the right float cylinder 76. By utilizing both the first right rod-side accumulator 96 and the second right rod-side accumulator 148, the first right rod-side volume or space 98 and the second right rod-side volume or space 150 combine to impart a first float response to the rod-side fluid port 90 of the right float cylinder 76. This configuration maximizes the available compressible volume or space of the accumulators 84, 96, 142, 148, effectively reducing the spring rates provided by the hydraulic system 36 to the left and right float cylinders 72, 76, respectively.

[0064] refer to Figure 3, describes the control of the fluid circuit 42 for controlling the header linkage system 44 in a second float state. The second float state of the hydraulic system 36 includes the left and right float control valves 82, 94 positioned in their respective closed positions. The first left accumulator control valve 140 and the first right accumulator control valve 146 are positioned in their respective closed positions. This configuration allows only the second left rod-side accumulator 142 to communicate with the rod-side fluid port 78 of the left float cylinder 72. By using only the second left rod-side accumulator 142, only the second left rod-side volume or space 144 is available for applying the second float response to the rod-side fluid port 78 of the left float cylinder 72. Furthermore, this configuration allows only the second right rod-side accumulator 148 to communicate with the rod-side fluid port 90 of the right float cylinder 76. By using only the second right rod-side accumulator 148, only the second right rod-side volume or space 150 is available for applying the second float response to the rod-side fluid port 90 of the right float cylinder 76. This configuration limits the available compressible volume or space to only the second left and right rod-side volumes or spaces 144 and 150, effectively increasing the spring rates provided by the hydraulic system 36 to the left and right floating cylinders 72 and 76, respectively.

[0065] refer to Figure 5 , an alternative embodiment of a hydraulic system is shown generally at 200. Figures 1 to 4 The reference numerals of the features in Figure 5 The same features in Figure 5 The hydraulic system 200 shown in FIG. Figures 3 and 4 The lifting cylinder 58 and the lifting control valve 60 shown in FIG. Figure 5 The hydraulic system 200 shown in FIG. 2 includes a second left accumulator control valve 202 and a second right accumulator control valve 204 .

[0066] The second left accumulator control valve 202 is positioned to control the second left rod-side accumulator 142. The second left accumulator control valve 202 is selectively controllable between an open position and a closed position. When the second left accumulator control valve 202 is set in the open position, the second left accumulator control valve 202 allows fluid communication between the second left rod-side accumulator 142 and the rod-side fluid port 78 of the left floating cylinder 72. When the second left accumulator control valve 202 is set in its open position, thereby allowing fluid communication between the second left rod-side accumulator 142 and the rod-side fluid port 78 of the left floating cylinder 72, the first left accumulator control valve 140 can be controlled so that the hydraulic system 200 can operate in the first floating state or the second floating state, as described above with reference to Figure 3 and Figure 4 described.

[0067] When the second left accumulator control valve 202 is set in the closed position, the second left accumulator control valve 202 blocks fluid communication between the second left rod-side accumulator 142 and the rod-side fluid port 78 of the left float cylinder 72. When the second left accumulator control valve 202 is set in the closed position, the first left accumulator control valve 140 can be controlled to its corresponding closed position, thereby blocking fluid communication between the first left rod-side accumulator 84 and the rod-side fluid port 78 of the left float cylinder 72. In this configuration, the left float control valve 82 can be controlled to operate the header linkage system 44 in the lift state to raise and lower the header linkage system 44, thereby functionally providing lift to the header linkage system 44.

[0068] The second right accumulator control valve 204 is positioned to control the second right rod-side accumulator 148. The second right accumulator control valve 204 is selectively controllable between an open position and a closed position. When the second right accumulator control valve 204 is set in the open position, the second right accumulator control valve 204 allows fluid communication between the second right rod-side accumulator 148 and the rod-side fluid port 90 of the right floating cylinder 76. When the second right accumulator control valve 204 is set in its open position, allowing fluid communication between the second right rod-side accumulator 148 and the rod-side fluid port 90 of the right floating cylinder 76, the first right accumulator control valve 146 can be controlled so that the hydraulic system 200 can operate in the first floating state or the second floating state, as described above with reference to Figure 3 and Figure 4 described.

[0069] When the second right accumulator control valve 204 is set in the closed position, the second right accumulator control valve 204 blocks fluid communication between the second right rod-side accumulator 148 and the rod-side fluid port 90 of the right float cylinder 76. When the second right accumulator control valve 204 is set in the closed position, the first right accumulator control valve 146 can be controlled to its corresponding closed position, thereby blocking fluid communication between the first right rod-side accumulator 96 and the rod-side fluid port 90 of the right float cylinder 76. In this configuration, the right float control valve 94 can be controlled to operate the header linkage system 44 in the lift state to raise and lower the header linkage system 44, thereby functionally providing lift to the header linkage system 44.

[0070] Therefore, in Figure 5 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 and 4 The lift function shown is performed by lift cylinder 58 and lift control valve 60 .

[0071] 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.

[0072] 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. An agricultural machine (20), comprising: Frame (22); a header linkage system (44) attached to the frame (22) and configured for attaching a cutter head (46) to the frame (22); a tank (40) operable to store a supply of fluid; a pressure source (38) in fluid communication with the tank (40) and operable to receive fluid from the tank (40) and circulate the fluid through a fluid circuit (42); a float cylinder (72, 76) interconnecting the header linkage system (44) and the frame (22), the float cylinder (72, 76) including a rod-side fluid port (78) in fluid communication with the pressure source (38); a first rod-side accumulator (84, 96) in fluid communication with the rod-side fluid port (78) of the floating cylinder (72, 76); a second rod-side accumulator (142, 148) in fluid communication with the rod-side fluid port (78) of the floating cylinder (72, 76); A first accumulator control valve (140, 146) is positioned to control the first rod-side accumulator (84, 96), wherein the first accumulator control valve (140, 146) is selectively controllable between an open position and a closed position in a floating operating state of the header linkage system, the open position allowing fluid communication between the first rod-side accumulator (84, 96) and the rod-side fluid port (78) of the float cylinder (72, 76), and the closed position preventing fluid communication between the first rod-side accumulator (84, 96) and the rod-side fluid port (78) of the float cylinder (72, 76), so that the header linkage system exhibits different floating responses in the floating operating state.

2. The agricultural machine (20) according to claim 1, wherein When the first accumulator control valve (140, 146) is set to the open position, the first rod-side accumulator (84, 96) and the second rod-side accumulator (142, 148) jointly apply a first floating response to the rod-side fluid port (78) of the floating cylinder (72, 76), and when the first accumulator control valve (140, 146) is set to the closed position, only the second rod-side accumulator (142, 148) applies a second floating response to the rod-side fluid port (78) of the floating cylinder (72, 76), wherein the first floating response is slower than the second floating response.

3. The agricultural machine (20) according to claim 2 further includes a header controller (124), wherein the header controller (124) is configured to control the first accumulator control valve (140, 146) to be in an open position of the first accumulator control valve so that the header linkage system (44) operates in a first floating state with a first floating response exhibiting a first header floating return speed; and the header controller (124) is configured to control the first accumulator control valve (140, 146) to be in a closed position of the first accumulator control valve so that the header linkage system (44) operates in a second floating state with a second floating response exhibiting a second header floating return speed.

4. The agricultural machine (20) according to claim 1, wherein The first rod-side accumulator (84, 96) defines a first volume (86) that is compressible in response to a fluid pressure above a defined first set point, and wherein the second rod-side accumulator (142, 148) defines a second volume (144) that is compressible in response to a fluid pressure above a defined second set point.

5. The agricultural machine (20) according to claim 4, wherein The first volume (86) is equal to the second volume (144).

6. The agricultural machine (20) according to claim 4, wherein: The first volume (86) is not equal to the second volume (144).

7. The agricultural machine (20) according to claim 4, wherein: The defined first set point is equal to the defined second set point.

8. The agricultural machine (20) according to claim 4, wherein: The defined first set point is not equal to the defined second set point.

9. The agricultural machine (20) of claim 1 further comprising a float control valve (82, 94) in fluid communication with the pressure source (38) and the rod-side fluid port (78) 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) 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) of the float cylinder (72, 76).

10. The agricultural machine (20) according to claim 9, wherein The first rod-side accumulator (84, 96) and the second rod-side accumulator (142, 148) are both positioned in fluid communication within the fluid circuit (42) and between the float cylinder (72, 76) and the float control valve (82, 94).

11. The agricultural machine (20) according to claim 9, wherein: The float cylinders (72, 76) are single-acting hydraulic cylinders operable to retract in response to receiving fluid into the rod-side fluid ports (78) of the float cylinders (72, 76) and to extend in response to gravity moving the header linkage system (44).

12. The agricultural machine (20) of claim 9, further comprising a second accumulator control valve (202, 204) positioned to control the second rod-side accumulator (142, 148), wherein the second accumulator control valve (202, 204) is selectively controllable between an open position allowing fluid communication between the second rod-side accumulator (142, 148) and the rod-side fluid port (78) of the float cylinder (72, 76) and a closed position preventing fluid communication between the second rod-side accumulator (142, 148) and the rod-side fluid port (78) of the float cylinder (72, 76).

13. The agricultural machine (20) of claim 12, further comprising a header controller (124), the header controller (124) being configured to simultaneously control the first accumulator control valve (140, 146) to be in its closed position and the second accumulator control valve (202, 204) to be in its closed position when the float control valve (82, 194) is opened, thereby operating the header linkage system (44) in a raised state to raise the header linkage system (44) relative to the frame (22).

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