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US-12622361-B2 - Regenerative tailgate circuit

US12622361B2US 12622361 B2US12622361 B2US 12622361B2US-12622361-B2

Abstract

An agricultural baler tailgate control system having an actuator operatively connected between the baler frame and tailgate, a pump, and a drive circuit. The drive circuit is reconfigurable between a first configuration in which the drive circuit conveys pressurized fluid by a first fluid path from the pump to the actuator to generate a first actuator drive force to move the tailgate from the closed tailgate position to an intermediate tailgate position, and a second configuration in which the drive circuit conveys the pressurized fluid by a second fluid path from the pump to the actuator to generate a second actuator drive force to move the tailgate from the intermediate tailgate position to a bale release position. The second actuator drive force is different from the first actuator drive force.

Inventors

  • Kevin Smith

Assignees

  • CNH INDUSTRIAL AMERICA LLC

Dates

Publication Date
20260512
Application Date
20240814

Claims (12)

  1. 1 . A tailgate control system for an agricultural baler having a frame, a tailgate mounted to the frame and movable relative to the frame through a travel range extending between a closed tailgate position and a bale release position, and a baling chamber defined between the frame and the tailgate, the tailgate control system comprising: an actuator operatively connected between the frame and the tailgate; a pump; and a drive circuit configured to convey pressurized fluid from the pump to the actuator, wherein the drive circuit is reconfigurable between a first configuration in which the drive circuit conveys the pressurized fluid by a first fluid path from the pump to the actuator to generate a first actuator drive force to move the tailgate from the closed tailgate position to an intermediate tailgate position between the closed tailgate position and the bale release position, and a second configuration in which the drive circuit conveys the pressurized fluid by a second fluid path from the pump to the actuator to generate a second actuator drive force to move the tailgate from the intermediate tailgate position to the bale release position, wherein the second actuator drive force is different from the first actuator drive force, wherein the drive circuit comprises a fluid path valve that is movable in a first direction to move the drive circuit from the first configuration to the second configuration, and in a second direction to move the drive circuit from the second configuration to the first configuration, wherein the actuator includes a cylinder having a proximal cylinder end and a distal cylinder end, a piston telescopically movable within the cylinder and hydraulically dividing the cylinder into a base chamber and a rod chamber, and a rod having a proximal rod end secured to the piston and a distal end extending through the rod chamber and through the distal cylinder end, and wherein the fluid path valve is configured to in the first configuration, fluidly connect the pressurized fluid from an outlet of the pump to the base chamber and the rod chamber, and in the second configuration, fluidly connect the pressurized fluid from the outlet of the pump to the base chamber, and fluidly connect the rod chamber to a fluid return.
  2. 2 . The tailgate control system of claim 1 , wherein the second actuator drive force is greater than the first actuator drive force.
  3. 3 . The tailgate control system of claim 1 , further comprising at least one valve controller configured to remotely move the fluid path valve in at least one of the first direction and the second direction.
  4. 4 . The tailgate control system of claim 3 , further comprising a control unit operatively connected to the actuator and configured to control the actuator based on a feedback signal.
  5. 5 . The tailgate control system of claim 4 , wherein the feedback signal comprises a signal from a position sensor indicating a position of the tailgate along the travel range.
  6. 6 . The tailgate control system of claim 4 , wherein the feedback signal comprises a signal from a pressure sensor indicating a pressure in the actuator.
  7. 7 . A method for operating an actuator configured to move a tailgate of a baler relative to a frame of the baler through a travel path from a closed tailgate position to a bale release position, the method comprising: connecting the actuator to a source of pressurized fluid by a first fluid path to generate a first actuator drive force to move the tailgate from the closed tailgate position to an intermediate tailgate position between the closed tailgate position and the bale release position; and connecting the actuator to the source of pressurized fluid by a second fluid path to generate a second actuator drive force to move the tailgate from the intermediate tailgate position to the bale release position, wherein the first fluid path comprises a regenerative fluid path in which a base chamber and a rod chamber of the actuator are fluidly connected to the source of pressurized fluid, and the second fluid path comprises a single-side fluid path in which only the base chamber is connected to the source of pressurized fluid.
  8. 8 . The method of claim 7 , wherein the second actuator drive force is greater than the first actuator drive force.
  9. 9 . The method of claim 7 , wherein the first fluid path and the second fluid path are defined in a single movable valve.
  10. 10 . The method of claim 7 , further comprising: receiving a sensor signal indicating that the tailgate is in the intermediate tailgate position; and operating a valve to change the first fluid path to the second fluid path.
  11. 11 . The method of claim 10 , wherein the sensor signal comprises: an angular position sensor signal indicating an angular position of the tailgate relative to the frame; or a pressure sensor signal indicating a pressure of hydraulic fluid in the first fluid path.
  12. 12 . The method of claim 7 , further comprising applying a bale drive force to bias the tailgate from the closed tailgate position towards the bale release position, during at least a portion of time in which the actuator is connected to the source of pressurized fluid by the first fluid path.

Description

CROSS REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Patent Application Ser. No. 63/532,719, filed Aug. 15, 2023, the content of such application being incorporated by reference herein in its entirety. FIELD OF THE INVENTION The present invention pertains to agricultural balers. BACKGROUND OF THE INVENTION Agricultural harvesting machines, such as balers, are used to consolidate and package crop material so as to facilitate the storage and handling of the crop material for later use. In the case of hay or silage, a mower-conditioner is typically used to cut and condition the crop material. In the case of straw, an agricultural combine discharges non-grain crop material from the rear of the combine defining the straw (such as wheat or oat straw) which is to be picked up by the baler. The cut crop material typically is raked into a windrow, and a baler, such as a large square baler or round baler, straddles the windrows and travels along the windrows to pick up the crop material and form it into bales. A round baler may generally include a frame, supported by wheels, a hydraulic system, a pickup unit to engage and lift the crop material into the baler, a cutting assembly, a main bale chamber for forming a bale, and a wrapping mechanism for wrapping or tying a material around the bale after it has been formed in the main bale chamber. As the baler is towed over a windrow, the pickup unit lifts the crop material into the baler. Then, the crop material may be cut into smaller pieces by the cutting assembly. As the crop material enters the main bale chamber, multiple carrier elements, e.g. rollers, chains and slats, and/or belts, will begin to roll a bale of hay within the chamber. These carrier elements are movable so that the chamber can initially contract and subsequently expand to maintain an appropriate amount of pressure on the periphery of the bale. After the bale is formed and wrapped by the wrapping mechanism, the baler's tailgate is opened to eject the bale by allowing the bale to fall out onto the field. The baler usually is stopped in place on the field during bale ejection, in order to help control the bale position and prevent damage to the bale wrapping and potentially the bale itself as it contacts the ground. The total time for the ejection process depends in some part on how long it takes to open the tailgate. A typical agricultural baler uses a hydraulically powered system to open the tailgate when the bale is ready to be ejected. However, such systems can act relatively slowly, particularly in balers having relatively low-powered hydraulic systems, leading to longer ejection process time and therefore reduced harvesting efficiency. Slow tailgate opening also can cause damage to the bale wrapping as the bale continues to contact the carrier elements and tailgate while the tailgate opens. The problem of slow tailgate opening can be addressed, at least to some degree, by increasing the pressure of the hydraulic circuit. However, this requires a more robust construction to handle operating loads, and potentially leads to significant cost increases for balers having lower-powered hydraulic systems. It is also known to use mechanical systems to operate the tailgate at different speeds, but such systems are expected to add complexity and service requirements. The inventor has determined that further improvements can be made to agricultural baler machines. This description of the background is provided to assist with an understanding of the following explanations of exemplary embodiments, and is not an admission that any or all of this background information is necessarily prior art. SUMMARY OF THE INVENTION In a first exemplary aspect, there is provided a tailgate control system for an agricultural baler having a frame, a tailgate mounted to the frame and movable relative to the frame through a travel range extending between a closed tailgate position and a bale release position, and a baling chamber defined between the frame and the tailgate. The tailgate control system includes: an actuator operatively connected between the frame and the tailgate; a pump; and a drive circuit configured to convey pressurized fluid from the pump to the actuator. The drive circuit is reconfigurable between: a first configuration in which the drive circuit conveys the pressurized fluid by a first fluid path from the pump to the actuator to generate a first actuator drive force to move the tailgate from the closed tailgate position to an intermediate tailgate position between the closed tailgate position and the bale release position, and a second configuration in which the drive circuit conveys the pressurized fluid by a second fluid path from the pump to the actuator to generate a second actuator drive force to move the tailgate from the intermediate tailgate position to the bale release position, wherein the second actuator drive force is different from the first actuator drive