Automated work tool pressure reduction circuit and method

Abstract

A control system (101) is disclosed for depressurizing a work tool auxiliary circuit (400) in fluid communication with a work tool (116) that couples to a work machine (100) by a quick coupler (114). The system (101) may include a controller (120) configured to receive an unlock signal for the work tool (116), receive tool data associated with the work tool (116), the tool data including a target pressure for the work tool auxiliary circuit (400) or an opening time for a relief valve (408), and, in response to the unlock signal and the tool data, automatically actuate the relief valve (408) to open (a) for the opening time, or (b) until the target pressure is reached in the work tool auxiliary circuit (400) or machine-side circuit (412), or (c) to reach and maintain the target pressure in the work tool auxiliary circuit (400) or machine-side circuit (412).

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates generally to hydraulic systems for work machines, and more particularly to reducing pressure in hydraulic work tool auxiliary circuits. [Background technology]

[0002] Work machines, such as excavators, backhoes, skid steers, wheel loaders, tractors, and the like, are further equipped with quick couplers that are used to attach and detach various work tool attachments, commonly referred to as implements, to the work machine. More specifically, some implements are coupled at the end of the work assembly, commonly referred to as the boom and arm of the work machine. Quick couplers are typically industrial components for heavy equipment that enable quick and efficient exchange of buckets, hammers, grapples, compactors, rakes, and other implements onto the arm of the work machine. Without a quick coupler, an operator would need to manually drive out the pin, typically using a hammer.

[0003] Hydraulic coupling quick couplers are an improvement over standard quick couplers. Standard quick couplers only physically connect the work implement to the machine, still requiring manual connection of hydraulic lines. Hydraulic coupling quick couplers, if equipped, physically connect both the implement and hydraulic lines to the machine. Hydraulic coupling quick couplers allow the work machine to quickly switch between different hydro-mechanical or hydro-mechanical work tools by using the work machine's hydraulic system and can be operated by controls from the work machine's cab. The work machine's hydraulic system typically connects to the quick coupler through hydraulic lines from the hydraulic system. The hydraulic lines typically run throughout the work machine. The hydraulic lines typically utilize hydraulic couplings that form fluid-tight seals to maintain hydraulic fluid pressure within the circuit.

[0004] U.S. Patent Publication No. 2020 / 0217040, published July 9, 2020, discloses a coupler for connecting an attachment to an excavator or other machine, the coupler including an electric actuator for locking and unlocking a locking member, a first power coupling unit, and a second actuator for moving the power coupling unit into and out of an engaged position engageable with a corresponding second power coupling unit of the attachment. The coupler is configured to move the first power coupling unit to the engaged position after the latch member assumes the locked state, and to keep the latch member locked until the first power coupling unit is disengaged from the engaged position when the attachment is removed from the coupler. While beneficial, there is a need for an improved hydraulic system that facilitates connecting and disconnecting work implements from quick couplers. Summary of the Invention

[0005] According to one aspect of the present disclosure, a control system is disclosed for depressurizing a work tool auxiliary circuit in fluid communication with a work tool coupled to a work machine by a quick coupler. The work tool may include a work tool valve block. The quick coupler may include a quick coupler valve block and a locking member movable between a locked position and an unlocked position. When in the locked position, the work tool valve block and the quick coupler valve block may be mated and in fluid communication. When in the unlocked position, the work tool valve block and the quick coupler valve block may be removable. The work tool auxiliary hydraulic circuit may include a reservoir and a relief valve in fluid communication with the quick coupler valve block and the fluid reservoir. The system may include a controller configured to receive a work tool unlock signal, receive tool data associated with the work tool, the tool data including a target pressure for the work tool auxiliary circuit or an open time for the relief valve, and, in response to the unlock signal and the tool data, automatically actuate opening the relief valve (a) for the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit or machine-side circuit, or (c) to reach and maintain the target pressure in the work tool auxiliary circuit or machine-side circuit.

[0006] According to another aspect of the present disclosure, a method for depressurizing a work tool auxiliary circuit in fluid communication with a work tool coupled to a work machine by a quick coupler is disclosed. The work tool may include a work tool valve block. The quick coupler may include a quick coupler valve block and a locking member movable between a locked position and an unlocked position. The work tool auxiliary hydraulic circuit may include a reservoir and a first relief valve in fluid communication with the quick coupler valve block and the fluid reservoir. The method may include receiving a work tool unlock signal and receiving tool data associated with the work tool, the tool data including a target pressure for the work tool auxiliary circuit or an opening duration of the first relief valve, and automatically actuating, in response to the unlock signal and the tool data, to open the first relief valve and move the locking member to the unlocked position (a) for the opening duration, or (b) until the target pressure is reached in the work tool auxiliary hydraulic circuit or machine-side circuit, or (c) to reach and maintain the target pressure in the work tool auxiliary circuit or machine-side circuit.

[0007] According to another aspect of the present disclosure, a method of depressurizing a work tool auxiliary circuit in fluid communication with a work tool is disclosed. The work tool is connected to a work machine by a quick coupler. The work tool may include a work tool valve block. The quick coupler may include a quick coupler valve block and a locking member movable between a locked position and an unlocked position. The work tool auxiliary hydraulic circuit may include a reservoir and a first relief valve in fluid communication with the quick coupler valve block and the fluid reservoir. The method may include receiving a work tool lock signal; receiving tool data associated with the work tool, the tool data including a target pressure in the work tool auxiliary circuit or an open time for the first relief valve; and automatically actuating, by a controller, opening the first relief valve to reach and maintain the target pressure in the work tool auxiliary circuit or the machine-side circuit (a) during the open time; or (b) until the target pressure is reached in the work tool auxiliary circuit or the machine-side circuit; or (c) before and / or during locking of the quick coupler to the work tool by moving a locking member to a locked position; and moving the locking member from an unlocked position to a locked position to lock the quick coupler to the work tool.

[0008] These and other aspects and features of the present disclosure will be more readily understood from the following detailed description when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of an exemplary work machine utilizing the teachings of the present disclosure. [Figure 2] FIG. 2 is an enlarged perspective view of a quick coupler that connects to a work tool. [Figure 3] FIG. 3 is an enlarged perspective view of the quick coupler shown exploded from the work tool bracket. [Figure 4]FIG. 4 is a simplified exemplary schematic diagram of a control system for depressurizing an exemplary (hydraulic) work tool auxiliary circuit of a work machine. [Figure 5] FIG. 5 is a simplified exemplary schematic diagram illustrating a hydraulic circuit of a work machine with a work tool coupled to the work machine prior to depressurization, in accordance with one embodiment of the present disclosure. [Figure 6] FIG. 6 is a simplified exemplary schematic diagram illustrating a hydraulic circuit of a work machine with a work tool coupled to the work machine and a relief valve open during depressurization, in accordance with one embodiment of the present disclosure. [Figure 7] FIG. 7 is a simplified exemplary schematic diagram illustrating pressure within a hydraulic circuit of a work machine after pressure reduction and before a relief valve moves to a closed position, in accordance with one embodiment of the present disclosure. [Figure 8] FIG. 8 is a simplified exemplary schematic diagram illustrating pressures within a hydraulic circuit of a work machine after a work tool has been depressurized and removed from the work machine, in accordance with one embodiment of the present disclosure. [Figure 9] FIG. 9 is a simplified exemplary schematic diagram illustrating pressures within a hydraulic circuit of a work machine prior to engagement of a work tool subjected to pressure due to thermal expansion, in accordance with one embodiment of the present disclosure. [Figure 10] FIG. 10 is a simplified exemplary schematic diagram illustrating pressures within a hydraulic circuit of a work machine following engagement of the work tool that is the subject of FIG. 9, in accordance with one embodiment of the present disclosure. [Figure 11] FIG. 11 is a simplified exemplary schematic diagram illustrating pressure within a hydraulic work tool auxiliary circuit after engagement of the work tool that is the subject of FIG. 9 and after depressurization, according to one embodiment of the present disclosure. [Figure 12] FIG. 12 is a flow chart of one exemplary method for depressurizing a work tool auxiliary circuit during the process of disconnecting a work tool from a machine according to the present disclosure. [Figure 13] FIG. 13 is a flow diagram of one exemplary method for depressurizing a work tool auxiliary circuit of a machine during the process of coupling the work tool to the machine according to the present disclosure. [Figure 14]FIG. 14 is an enlarged view illustrating the locking member of the quick coupler in the locked position. [Figure 15] FIG. 15 is an enlarged view illustrating the locking member of the quick coupler in the unlocked position.

[0010] The figures illustrate one embodiment of the present invention for purposes of example only. Those skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods described herein may be used without departing from the principles described herein. DETAILED DESCRIPTION OF THE INVENTION

[0011] 1, there is shown an exemplary work machine 100, illustrated as an excavator. While the following detailed description describes exemplary aspects relating to an excavator, it will be understood that the description applies equally to the use of the present disclosure in other work machines, including, but not limited to, backhoes, front-end loaders, skid steers, wheel loaders, and tractors.

[0012] Work machine 100 includes a frame 102 that supports an engine 104. Frame 102 is supported on ground engaging elements 106, illustrated as tracks. It is contemplated that ground engaging elements 106 may be any other type of ground engaging element 106, such as wheels. Work machine 100 further includes a work assembly 108 extending from frame 102 for performing work, such as excavating terrain or moving earth, soil, or other material at an excavation site. Frame 102 may be a rotating superstructure common to excavators and work machines in the agricultural and construction industries.

[0013] As illustrated, in one embodiment, work assembly 108 may include a boom 110, an arm 112, a quick coupler 114 that couples to arm 112, and a work tool 116 configured to remove earth, soil, and other materials from a work site. Work tool 116 may be a bucket, dipper, hammer, thumb, hydro-mechanical tool, or other attachment that couples to quick coupler 114 for operation by work machine 100.

[0014] Work machine 100 utilizes quick coupler 114 to attach and detach work tool 116 to work machine 100. Work tool 116 is configured to be attached / detached to quick coupler 114 and one or more hydraulic lines 118 disposed on the work machine. In the exemplary embodiment, quick coupler 114 is a hydraulic linkage quick coupler configured to connect to multiple hydraulic lines 118.

[0015] Referring now to FIG. 2, quick coupler 114 is illustrated coupled to work tool 116. As shown in FIG. 2, quick coupler 114 is attached to work tool bracket 200, which is in turn attached to work tool 116. FIG. 3 illustrates quick coupler 114 shown exploded from work tool bracket 200. As shown in FIG. 3, work tool bracket 200 may include a bracket frame 202 defining a cavity 204. Work tool bracket 200 may further include a work tool valve block 302 configured to mate with quick coupler valve block 300. Work tool valve block 302 may be disposed within cavity 204.

[0016] As illustrated in FIG. 3 , the quick coupler 114 includes a quick coupler valve block 300 configured to mate with a work tool valve block 302 (of the work tool bracket 200). The quick coupler 114 further includes one or more locking members 306 ( FIGS. 14-15 ) movable between an unlocked position 308 ( FIG. 15 ) and a locked position 310 ( FIG. 14 ). In the exemplary embodiment, the quick coupler 114 includes a primary locking member 306 a and a secondary locking member 306 b. The locking members 306 (e.g., primary locking member 306 a and secondary locking member 306 b) are configured to removably secure the quick coupler 114 to the work tool 116 ( FIGS. 14-15 ). The quick coupler 114 and the work tool bracket 200 may be fully coupled when secured by the locking members 306 (e.g., primary locking member 306 a and secondary locking member 306 b). When the quick coupler 114 and work tool bracket 200 are fully coupled, the quick coupler valve block 300 and the work tool valve block 302 allow flow to pass between the work tool 116 and the quick coupler 114. On the other hand, when the quick coupler 114 and the work tool bracket 200 are fully detached, the quick coupler valve block 300 and the work tool valve block 302 are detached and no flow can pass between the work tool 116 and the quick coupler 114. The quick coupler valve block 300 and the work tool valve block 302 are also collectively referred to as the hydraulic block 206. The quick coupler valve block 300 is configured to be fluidly connected to and detached from the work tool valve block 302. Similarly, the work tool valve block 302 is configured to be fluidly connected to and detached from the quick coupler valve block 300. The hydraulic lines 118 (FIG. 2) connect to the hydraulic coupling 304 (FIG. 3). Hydraulic coupling 304 is located within quick coupler valve block 300 and work tool valve block 302. Hydraulic coupling 304 is configured to form a fluid-tight seal.The hydraulic coupling 304 can have two components: a coupling body (socket or female end) and a coupling nipple (male end) that connect the hydraulic line 118 (FIG. 2) to the quick coupler valve block 300 of the quick coupler 114. Hydraulic coupling 304 (FIG. 3) connection types may include push-to-connect, pull-to-connect, threaded connections, quick-disconnect couplings, and universal interchanges commonly known in the art. The hydraulic coupling 304 can be configured with special features, such as a flush face design, a self-sealing poppet valve, a single or double shutoff valve, and a sleeve (automatic, manual, locking) to control leakage, air ingress, and controlled disconnection.

[0017] One or more of the hydraulic lines 118 (FIG. 2) may be utilized for the primary operation of the work tool 116, and one or more of the hydraulic lines 118 may be utilized for secondary operations, such as rotating, tilting, opening and closing the work tool 116. One or more of the hydraulic lines 118 may be utilized to supply hydraulic fluid from a pressure source 402 (see FIG. 4) to a work tool auxiliary circuit 400 configured to supply hydraulic fluid to a work tool 116 coupled to the work machine 100 (e.g., arm 112).

[0018] 4 illustrates a simplified example control system 101 for depressurizing an example work tool auxiliary circuit 400 of a work machine 100. For clarity, the schematic of FIG. 4 illustrates work tool auxiliary circuit 400 for certain functions, however, for other functions, additional elements (e.g., control valve 406, relief valve 408, etc.) may be utilized. Work tool auxiliary circuit 400 includes a machine-side circuit 412 and a two-side circuit 414 located on work machine 100. Work tool auxiliary circuit 400 may include one or more pressure sensors 426.

[0019] The tool-side circuit 414 (of the work tool auxiliary circuit 400) may include one or more tool-side hydraulic lines 416 disposed on / in the work tool 116 configured to carry hydraulic fluid from the work tool 116 to the work tool valve block 302 or to carry hydraulic fluid received from the work tool valve block 302 to the work tool 116.

[0020] A machine-side circuit 412 (of the work tool auxiliary circuit 400) is disposed on the work machine 100 and may include one or more hydraulic lines 118(a-d) configured to supply / carry hydraulic fluid, a pressure source 402, a reservoir 404, one or more control valves 406, one or more relief valves 408a, 408b, and one or more pressure-reducing lines 410(a-d) configured to supply / carry hydraulic fluid. The exemplary machine-side circuit 412 may include one or more pressure sensors 426. While the exemplary embodiment shown in FIG. 4 shows only one control valve 406 and two relief valves 408, in other embodiments there may be multiple control valves and more or fewer relief valves 408.

[0021] The control valve 406 is configured to regulate the distribution of hydraulic fluid pumped by the pressure source 402 throughout the work tool auxiliary circuit 400. The control valve 406 is movable between a shut-off position 418 and one or more flow positions 420. In the shut-off position 418, the control valve 406 is configured to prevent hydraulic fluid from flowing through the control valve 406. In each of the flow positions 420, the control valve 406 is configured to allow hydraulic fluid to enter, flow through, and exit the control valve 406. The control valve 406 may be a spool valve, a directional control valve, an electronically controlled valve, or the like. In the exemplary embodiment of FIG. 4, the control valve 406 is fluidly connected to the pressure source 402 by hydraulic line 118a, and the control valve 406 is fluidly connected to the quick coupler valve block 300 (of the hydraulic block 206) by hydraulic lines 118b, 118c. Additionally, control valve 406 is in fluid communication with reservoir 404 by hydraulic line 118d. Control valve 406 is also in fluid communication with relief valves 408a, 408b via hydraulic lines 118b, 118c to apply pressure to lines 410a, 410b.

[0022] Each relief valve 408a, 408b is configured to be movable between a closed position 422 and an open position 424. In the closed position 422, the relief valves 408a, 408b are configured to prevent hydraulic fluid from flowing through them. When in the open position 424, the relief valves 408a, 408b are configured to allow hydraulic fluid to enter, pass through, and exit the relief valves 408a, 408b. The relief valves 408 may be electromechanical valves, including, but not limited to, pressure-reducing valves, directional control valves, pressure control valves, flow control valves, solenoid valves, or other valves. In an exemplary embodiment, each relief valve 408a, 408b may be a solenoid pressure release valve (e.g., a proportional pressure release valve). The relief valves 408 may also be utilized for functions other than reducing pressure (e.g., controlling work tool operating pressure during tool use). 4, relief valves 408a, 408b are fluidly connected to control valve 406 and to quick coupler valve block 300 (of hydraulic block 206) via pressure reduction lines 410a, 410b and hydraulic lines 118b, 118c, respectively. Relief valves 408a, 408b are also fluidly connected to reservoir 404 via pressure reduction lines 410c, 410d and hydraulic line 118d. Relief valves 408a, 408b are further configured to relieve pressure in work tool auxiliary circuit 400, for example, by fluidly connecting pressure reduction lines 410a, 410b to reservoir 404 via pressure reduction lines 410c, 410d and hydraulic line 118d.

[0023] The pressure sensor 426 is configured to measure the fluid pressure. In the exemplary embodiment described herein, the pressure sensor 426 is located upstream of and adjacent to the relief valves 408a, 408b.

[0024] Pressure source 402 is configured to supply hydraulic fluid under pressure to work tool auxiliary circuit 400. For example, pressure source 402 can be configured to pump hydraulic fluid throughout work tool auxiliary circuit 400 (when relief valves 408a, 408b are in closed position 422, as shown in FIG. 4 ) to create pressure in multiple hydraulic lines 118(a-d) and one or more pressure reduction lines 410a, 410b. Pressure source 402 may be a pump or other pressure source known to those skilled in the art. In the exemplary embodiment of FIG. 4 , pressure source 402 is in fluid communication with control valve 406 by hydraulic line 118a.

[0025] Reservoir 404 is configured to store a supply of hydraulic fluid. Reservoir 404 may be a tank or the like configured to store hydraulic fluid. As generally known in the art, work tool auxiliary circuit 400 may utilize a variety of hydraulic fluids stored and supplied in reservoir 404, such as oil, water, gas, or other commonly known fluids used in hydraulic circuits and systems. In the exemplary embodiment of FIG. 4 , reservoir 404 is in fluid communication with control valve 406 by hydraulic line 118d and with relief valves 408a, 408b by hydraulic line 118d and pressure relief lines 410c, 410d.

[0026] The control system 101 for reducing pressure in the work tool auxiliary circuit 400 includes a controller 120. The control system 101 may further include an operator interface 122. The control system 101 may further include a transmitter 124.

[0027] The operator interface 122 is configured to communicate with the controller 120, receive user input, and send a signal (e.g., an unlock signal, a lock signal) to the controller 120 based on the user input (e.g., pressing a switch).

[0028] Transmitter 124 may be located on work tool 116 or on work machine 100. Transmitter 124 is in communication with controller 120 and is configured to transmit tool data associated with work tool 116 to controller 120.

[0029] Controller 120 is configured to control the reduced pressure in work tool auxiliary circuit 400. Controller 120 is configured to receive an unlock signal (based on user input) from operator interface 122 to unlock quick coupler 114. Controller 120 is further configured to receive a lock signal (based on user input) from operator interface 122 to lock quick coupler 114. Controller 120 is further configured to receive / retrieve tool data associated with work tool 116 from operator interface 122, transmitter 124, and / or memory component 128.

[0030] The controller 120 may be configured to send control signals to the control valve 406 to move the control valve 406 from the shut-off position 418 to the flow position 420 and vice versa, and may be configured to send control signals to the relief valves 408a, 408b to move the relief valves 408a, 408b from the closed position 422 to the open position 424 and vice versa.

[0031] Controller 120 may include a processor 126 and a memory component 128. Controller 120 may be in operative communication with operator interface 122 and configured to receive / acquire tool data associated with work tool 116 from operator interface 122. Controller 120 may be in operative communication with transmitter 124 and configured to receive tool data associated with work tool 116 from transmitter 124. Controller 120 may be in operative communication with pressure sensor 426 and configured to receive / acquire one or more pressure measurements from the pressure sensor associated with work tool auxiliary circuit 400 or machine-side circuit 412.

[0032] In some embodiments, the controller 120 may be configured to actuate the unlocking of the quick coupler 114 (and hydraulic block 206) by actuating the movement of one or more locking members 306 (FIGS. 14-15) to an unlocked position 308, and in some embodiments, the controller 120 may be configured to actuate the locking of the quick coupler 114 (and hydraulic block 206) by actuating the movement of one or more locking members 306 to a locked position 310.

[0033] In response to the unlock signal, the controller 120 may be configured to automatically actuate one or more relief valves 408 a, 408 b to open for an open time or until a target pressure is reached in (a portion of) the work tool auxiliary circuit 400 (e.g., in hydraulic lines 118(b, c) and reduced-pressure lines 410(a, b) and tool-side hydraulic line 416). The pressure (target pressure) in the work tool auxiliary circuit 400 (e.g., hydraulic lines 118(b, c) and reduced-pressure lines 410(a, b) and tool-side hydraulic line 416) may be measured by one or more pressure sensors 426. In one exemplary embodiment, such pressure in the work tool auxiliary circuit 400 may be measured upstream of and near the relief valve 408. The controller 120 may be configured to actuate the quick coupler 114 to move the locking member 306 (e.g., primary locking member 306 a, secondary locking member 306 b) from the locked position 310 to the unlocked position 308. When locking members 306 (e.g., in the exemplary embodiment, primary locking member 306a, secondary locking member 306b) are in unlocked position 308, work tool valve block 302 and quick coupler valve block 300 may be removable (and work tool 116 may be removable from quick coupler 114 of work machine 100).

[0034] In response to the lock signal, the controller 120 may be configured to automatically actuate one or more relief valves 408 a, 408 b to open for an open time or until a target pressure is reached in (a portion of) the machine-side circuit 412 (e.g., in the hydraulic lines 118(b, c) and the reduced-pressure lines 410(a, b)). The pressure (target pressure) in the machine-side circuit 412 (e.g., in the hydraulic lines 118(b, c) and the reduced-pressure lines 410(a, b)) may be measured by one or more pressure sensors 426. In one exemplary embodiment, such pressure in the machine-side circuit 412 may be measured upstream of and near the relief valves 408. In some embodiments, the controller 120 may automatically actuate the quick coupler 114 to move the locking members 306 (e.g., in the exemplary embodiment, primary locking member 306 a, secondary locking member 306 b) from the unlocked position 308 to the locked position 310 to lock the work tool 116 to the quick coupler valve block 300.

[0035] In some embodiments, the controller 120 can continue to maintain / adjust the pressure near the target pressure by maintaining one or more relief valves 408a, 408b in the open position 424 as needed to maintain the target pressure during locking (movement of the locking member 306 (e.g., in the exemplary embodiment, the primary locking member 306a, secondary locking member 306b to the locked position 310)) or unlocking (movement of the locking member 306 (e.g., in the exemplary embodiment, the primary locking member 306a, secondary locking member 306b to the unlocked position 308)).

[0036] Processor 126 may be a microcontroller, a digital signal processor (DSP), an electronic control module (ECM), an electronic control unit (ECU), a field programmable gate array (FPGA), a microprocessor, or any other suitable processor known in the art. Processor 126 can execute instructions and generate control signals for determining an open time or target pressure associated with a work tool, and / or for actuating a relief valve during the open time or until a target pressure is reached in work tool auxiliary circuit 400 or machine-side circuit 412, and / or for regulating / maintaining pressure (near the target pressure) during locking and / or unlocking of locking member 306. Such instructions may be loaded onto or embedded in a computer-readable medium, such as memory component 128, or may be provided external to processor 126. In alternative embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the control methodology.

[0037] As used herein, the term "computer-readable medium" refers to any non-transitory medium or combination of media that participates in providing instructions to processor 126 for execution. Such media may include all computer-readable media except for transitory propagating signals. Common forms of computer-readable media include, for example, floppy disks, flexible disks, hard disks, magnetic tape, or any other magnetic medium, CD-ROMs, any other optical medium, or any other computer-readable medium.

[0038] Controller 120 is not limited to one processor 126 and memory component 128. Controller 120 may include several processors 126 and memory components 128. In one embodiment, processor 126 may be parallel processors with access to a shared memory component 128. In another embodiment, processor 126 may be part of a distributed computing system, in which case processor 126 (and its associated memory component 128) may be located remotely from one or more other processors 126 (and associated memory component 128) or FPGAs that are part of the distributed computing system.

[0039] The controller 120 may also be configured to retrieve from the memory component 128 tool data, formulas, and other data necessary for the calculations and determinations described herein.

[0040] Also disclosed is a method of depressurizing a work tool auxiliary circuit 400 in fluid communication with a work tool 116 coupled to a work machine 100 by a quick coupler 114, the work tool 116 including a work tool valve block 302, the quick coupler 114 including a quick coupler valve block 300 and a locking member 306 movable between a locked position 310 and an unlocked position 308, and the work tool auxiliary circuit 400 including a reservoir 404 and a first relief valve 408 in fluid communication with the quick coupler valve block 300 and the fluid reservoir 404. The method may include receiving an unlock signal for the work tool 116 and receiving tool data associated with the work tool 116, the tool data including a target pressure for the work tool auxiliary circuit 400 or an open time for the first relief valve 408; and, in response to the unlock signal and the tool data, automatically actuating, by the controller 120, to open the first relief valve 408 (a) during the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit 400 or the machine-side circuit 412, or (c) before and / or during locking of the quick coupler 114 to the work tool 116 by moving the locking member 306 to a locked position 310 to reach and maintain the target pressure in the work tool auxiliary circuit 400 or the machine-side circuit 412; and moving the locking member 306 from the unlocked position 308 to the locked position 310 to lock the quick coupler 114 to the work tool 116.

[0041] Also disclosed is a method of depressurizing a work tool auxiliary circuit 400 in fluid communication with a work tool 116 coupled to a work machine 100 by a quick coupler 114, the work tool 116 including a work tool valve block 302, the quick coupler 115 including a quick coupler valve block 300 and a locking member 306 movable between a locked position 310 and an unlocked position 308, and the work tool auxiliary circuit 400 including a reservoir 404 and a first relief valve 408 in fluid communication with the quick coupler valve block 300 and the fluid reservoir 404. The method may include receiving a lock signal for the work tool 116 and receiving tool data associated with the work tool 116, the tool data including a target pressure for the work tool auxiliary circuit 400 or an open time for the first relief valve 408; and automatically actuating, by the controller 120, to open the first relief valve 408 to reach and maintain the target pressure in the work tool auxiliary circuit 400 or the machine-side circuit 412 by moving the locking member 306 to a locked position 310 (a) during the open time or (b) until the target pressure is reached in the work tool auxiliary circuit 400 or the machine-side circuit 412, or (c) before and / or during locking of the quick coupler 114 to the work tool 116; and moving the locking member 306 from the unlocked position 308 to the locked position 310 to lock the quick coupler 114 to the work tool 116. [Industrial Applicability]

[0042] In operation, the present disclosure may be applicable to many industries, including, but not limited to, construction, earthmoving, and agricultural industries. Specifically, the techniques of the present disclosure may be used to reduce hydraulic pressure in work machines 100, including, but not limited to, excavators, backhoes, skid steers, wheel loaders, tractors, etc., equipped with quick couplers 114 for easily connecting and disconnecting work tools 116, such as hammers, buckets, dippers, digging tools, etc. Although the foregoing detailed description is made with particular reference to excavators, it should be understood that the teachings thereof are also applicable to other work machines 100, such as, for example, backhoes, skid steers, wheel loaders, tractors, mulchers, etc.

[0043] In operation, the controller 120 can be configured to operate according to predetermined methods 1200-1300, for example as shown in FIGS.

[0044] FIG. 12 illustrates an exemplary flow chart showing sample blocks executed in a method 1200 of depressurizing a (hydraulic) work tool auxiliary circuit 400 of a work machine 100 .

[0045] Block 1210 includes receiving, by the controller 120, an unlock signal to unlock the quick coupler 114 so that the work tool 116 can be removed from the work machine 100. The unlock signal may be received from the operator interface 122 based on user input entered by an operator into the operator interface 122. For example, in one embodiment, the operator may flip a switch in an operator station to trigger transmission of the unlock signal (to unlock the work tool 116) from the operator interface 122 to the controller 120.

[0046] 5 is a simplified exemplary schematic diagram illustrating an exemplary (hydraulic) work tool auxiliary circuit 400 of a work machine 100 with the work tool 116 coupled to the work machine 100 prior to depressurizing and unlocking the work tool 116 from the work machine 100. As can be seen in FIG. 5, the control valve 406 is in a shut-off position 418. Hydraulic fluid may be under pressure in the hydraulic line 118a fluidly connecting the pressure source 402 to the control valve 406 and in the hydraulic lines 118b, 118c fluidly connecting the control valve 406 to the quick coupler valve block 300 (of the quick coupler 114). Additionally, the depressurization lines 410a, 410b may also be under pressure, as may the tool side hydraulic line 416 and passages (not shown) within the work tool 116 itself.

[0047] Block 1220 includes receiving / obtaining tool data associated with the work tool 116. The tool data may include tool identification information and / or a target pressure (associated with the work tool 116) for the work tool auxiliary circuit 400, and / or an open time associated with the work tool 116. The open time is the period of time that the first and / or second relief valves 408a, 408b remain open. The target pressure is the pressure in the work tool auxiliary circuit 400 (or machine-side circuit 412) at which the relief valves 408a, 408b close. The tool data can be received from the operator interface 122, the memory component 128, or from another source (e.g., a transmitter 124 located on the work tool 116 or work machine 100).

[0048] Block 1230 includes automatically actuating, in response to the unlock signal and based on tool data associated with the work tool 116, the controller 120 to open the first and / or second relief valves 408a, 408b (a) for an open time, or (b) until a target pressure is reached in the work tool auxiliary circuit 400, or (c) to reach and maintain the target pressure in the work tool auxiliary circuit 400. Block 1230 may include adjusting the pressure in the work tool auxiliary circuit 400 to the predetermined target pressure through a decoupling process.

[0049] 6 is a simplified exemplary schematic diagram illustrating a hydraulic work tool auxiliary circuit 400 of a work machine 100 having a work tool 116 coupled to the work machine 100 with relief valves 408a, 408b open during pressure reduction. As can be seen in FIG. 6, when relief valves 408a, 408b are open, hydraulic fluid is drained from hydraulic lines 118b, 118c (between control valve 406 and quick coupler valve block 300 (of quick coupler 114)) to reservoir 404 and from pressure reduction lines 410a, 410b to reservoir 404. Hydraulic fluid also evacuates from the associated work tool 116 through tool-side hydraulic line 416, work tool valve block 302 and quick coupler valve block 300 (of hydraulic block 206), and hydraulic lines 118b, 118c, and then through pressure-reducing lines 410a, 410b and relief valves 408a, 408b to reservoir 404. FIG. 7 is a schematic diagram illustrating the condition after pressure in the hydraulic circuit of work machine 100 has been reduced (to approximately 0 pounds per square inch (psi)) and before relief valves 408a, 408b have moved to a closed position 422 and hydraulic block 206 has been unlocked. As shown in FIG. 7, hydraulic line 118a between pressure source 402 and control valve 406 can remain pressurized.

[0050] Depending on the application, the release time of the pressure reduction process may need to be limited to limit tool drift (or the target pressure in the work tool auxiliary circuit 400 may need to be above 0 psi) before disengaging the quick coupler 114. Tool drift is the movement of the work tool 116 during a loss of hydraulic pressure in the work tool auxiliary circuit 400. For example, a thumb or grapple tine may currently be held open by hydraulic pressure in the work tool auxiliary circuit 400. When the hydraulic circuit of the work machine 100 is depressurized, the work tool 116 may begin to close or drift toward closing due to gravity and / or a lack of hydraulic pressure.

[0051] At block 1240, after the open time has expired or when a target pressure has been reached within the work tool auxiliary circuit 400 or a portion thereof (e.g., when the target pressure is reached as measured by a pressure sensor 426 positioned near the relief valves 408a, 408b), the method may further include unlocking the quick coupler 114 from the work tool 116 by moving the locking member 306 to the unlocked position 308. When the locking member 306 is in the unlocked position 308, the work tool 116 may be freely removed from the quick coupler 114. Before, during, or after unlocking, the controller may actuate the movement of the relief valves 408a, 408b to the closed position 422. FIG. 8 is an exemplary schematic diagram illustrating the work tool auxiliary circuit 400 of the work machine 100 after the work tool 116 has been depressurized and removed from the work machine 100. As can be seen in FIG. 8, the machine-side circuit 412 and the tool-side circuit 414 are depressurized.

[0052] FIG. 13 illustrates an exemplary flowchart showing sample blocks executed in a method 1300 of depressurizing the work tool auxiliary circuit 400 of the work machine 100 during a process for coupling the work tool 116 to the work machine 100. FIG. 9 is a schematic diagram illustrating pressures that may exist in the tool-side circuit 414 and the machine-side circuit 412 (see, e.g., tool-side hydraulic line 416) before the work tool 116 couples to the work machine 100. The pressure shown in the tool-side circuit 414 is typically a pressure due to thermal expansion, although such pressure may arise from other sources. If the work tool 116 is removed from the work machine 100 without depressurizing (depressurizing) the work tool auxiliary circuit 400 before removing the work tool 116, damage due to thermal expansion may occur as the pressure within the work tool 116 increases beyond the pressure tolerance of the work tool 116. For example, the work tool 116 may be capable of handling up to 3000 psi, and on a cold day the current pressure within the work tool 116 may be 2800 psi. If an operator removes work tool 116 from work machine 100 on a cold day when the pressure in work tool 116 is 2800 psi, and there is a large temperature change the day after work tool 116 is removed from work machine 100, the pressure in work tool 116 may increase significantly above the maximum design pressure due to thermal expansion of oil trapped within work tool 116 while work tool 116 is still removed from work machine 100. Reducing the pressure in work tool auxiliary circuit 400 reduces the force required to couple work tool valve block 302 to quick coupler valve block 300 (hydraulic block 206), improving the ease of coupling work tool 116 to work machine 100.

[0053] After the work tool 116 is picked up and coupled to the quick coupler 114, in block 1310 the controller 120 receives a lock signal to lock the work tool 116 to the quick coupler 114 to which it is currently attached (by locking the quick coupler valve block 300 to the work tool valve block 302). The lock signal may be received from the operator interface 122 based on a user input entered by an operator into the operator interface 122. For example, in one embodiment, the operator may flip a switch in an operator station to trigger transmission of the lock signal from the operator interface 122 to the controller 120.

[0054] Block 1320 includes receiving / obtaining, by the controller 120, tool data associated with the work tool 116, which may include tool identification information and / or a target pressure for the work tool auxiliary circuit 400 (associated with the work tool 116) or an open time (associated with the work tool 116).

[0055] At this point in the process, the control valve 406 is in the shut-off position 418. Block 1330 includes automatically actuating, by the controller 120, the opening of the first and second relief valves 408a, 408b to reach and maintain the target pressure in the work tool auxiliary circuit 400 or the machine-side circuit 412 by moving the locking member 306 to the locked position 310 (a) during the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit 400 or the machine-side circuit 412, or (c) before and / or during locking of the work tool 116 to the quick coupler valve block 300. In some embodiments, this pressure reduction can be initiated when the tool-side circuit 414 is not already in fluid communication with the machine-side circuit 412 (via the quick coupler valve block 300 and the work tool valve block 302) and can continue after the tool-side circuit 414 is in fluid communication with the machine-side circuit 412 (via the quick coupler valve block 300 and the work tool valve block 302). The inventors have discovered that if an operator inadvertently pressurizes the machine-side circuit 412 prior to fluid communication with the tool-side circuit 414, initiating a depressurization before fluid communication between the quick coupler valve block 300 and the work tool valve block 302 may facilitate such coupling between the quick coupler valve block 300 and the work tool valve block 302. In another embodiment, depressurization can be initiated once the tool-side circuit 414 is in fluid communication with the machine-side circuit 412.

[0056] FIG. 10 is a schematic diagram illustrating reduced pressure in the work tool auxiliary circuit 400 resulting from the opening of relief valves 408a, 408b.

[0057] In some embodiments, the quick coupler valve block 300 and the work tool valve block 302 may be in hydraulic fluid communication before locking. As such, the quick coupler valve block 300 and the work tool valve block 302 may be partially coupled (enough to allow fluid to flow therethrough, but the coupling process is not fully completed) or fully coupled (the coupling process is fully completed and fluid can flow freely therethrough). In one embodiment in which the quick coupler valve block 300 and the work tool valve block 302 are in hydraulic communication before the locking process, hydraulic fluid under internal pressure within the work tool 116 flows through the quick coupler valve block 300, hydraulic lines 118(b-d), and vacuum lines 410(a-d) to the reservoir 404.

[0058] In some cases, the quick coupler valve block 300 and the work tool valve block 302 may instead be configured to provide hydraulic communication during the locking process. In one embodiment in which the hydraulic coupling 304 provides hydraulic communication during the locking process, hydraulic fluid in the hydraulic lines 118(b-d) and the pressure-reducing lines 410(a-d) flows to the reservoir 404. When the hydraulic coupling 304 provides hydraulic communication, hydraulic fluid under internal pressure within the work tool 116 can flow through the quick coupler valve block 300, the hydraulic lines 118(b-d), and the pressure-reducing lines 410(a-d) to the reservoir 404.

[0059] Figure 11 is a schematic diagram illustrating the work tool auxiliary circuit 400 after pressure reduction. As can be seen in the embodiment shown in Figure 11, opening relief valves 408a, 408b reduces or removes internal pressure from the tool side circuit 414 and machine side circuit 412 (e.g., quick coupler valve block 300, hydraulic lines 118(b-d), and pressure reduction lines 410(a-d)). In one embodiment, hydraulic line 118a between pressure source 402 and control valve 406 may still be pressurized.

[0060] Block 1340 includes locking the quick coupler 114 to the work tool 116 after the open time expires or if a target pressure is reached in the work tool auxiliary circuit 400. In some embodiments, the controller may continue to regulate the pressure in the work tool auxiliary circuit 400 after the target pressure is reached by adjusting the opening of the first relief valve 408a and / or the second relief valve 408b. In one embodiment, the locking member 306 of the quick coupler 114 is moved from the unlocked position 308 to the locked position 310 to lock the quick coupler 114 and work tool 116 together. In some embodiments, as described above, the quick coupler valve block 300 and the work tool valve block 302 are in fluid communication during the locking of one or more of the locking members. Additionally, for quick coupler valve block 300 and work tool valve block 302 that are in fluid communication prior to the locking process, the quick coupler valve block 300 and work tool valve block 302 may be partially coupled, allowing flow to pass but not fully coupled. Allowing reduced pressure during the locking process facilitates complete seating of the quick coupler valve block 300 and work tool valve block 302, allowing for a good sealing fit.

[0061] From the above, it can be seen that the technology disclosed herein has industrial applicability in a variety of situations, such as, but not limited to, work machines 100 in the construction and agricultural industries that utilize quick couplers 114 to connect to various work tools 116.

Claims

1. 1. A control system (101) for reducing pressure in a work tool auxiliary circuit (400) in fluid communication with a work tool (116) coupled to a work machine (100) by a quick coupler (114), the work tool (116) comprising a work tool valve block (302), the quick coupler (114) comprising a quick coupler valve block (300) and a locking member (306) movable between a locked position (310) and an unlocked position (308), the quick coupler (114) being in the locked position (310). wherein the work tool valve block (302) and quick coupler valve block (300) are mated and in fluid communication, and when in the unlocked position (308), the work tool valve block (302) and quick coupler valve block (300) are removable, the work tool auxiliary circuit (400) comprises a reservoir (404) and a relief valve (408) in fluid communication with the quick coupler valve block (300) and the reservoir (404), and the system is A controller (120), receiving an unlock signal for the work tool (116); receiving tool data associated with the work tool (116), the tool data including a target pressure for the work tool auxiliary circuit (400) or an open time for the relief valve (408); and a controller configured to automatically actuate, in response to the unlock signal and the tool data, opening the relief valve (a) during the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit (400) or machine-side circuit (412), or (c) to reach and maintain the target pressure in the work tool auxiliary circuit (400) or machine-side circuit (412).

2. The control system (101) of claim 1, wherein the relief valve (408) is a solenoid pressure release valve.

3. The controller (120) is further configured to actuate the movement of the locking member (306) to the unlocked position (308), and the control system (101) is further configured to:

2. The control system of claim 1, comprising an operator interface in communication with the controller, the operator interface configured to receive user input, the unlock signal being received by the controller from the operator interface and based on the user input.

4. The controller (120) further comprises: receiving a lock signal for the work tool (116); receiving the tool data associated with the work tool (116); automatically actuating, by the controller (120), to open the relief valve (a) during the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit (400) or machine-side circuit (412), or (c) to reach and maintain the target pressure in the work tool auxiliary circuit (400) or machine-side circuit (412); and actuating movement of the locking member from the unlocked position to the locked position to lock the work tool valve block to the quick coupler valve block.

5. 2. The control system (101) of claim 1, wherein the tool data is received by the controller (120) from an operator interface (122), and the pressure in the work tool auxiliary circuit (400) or machine-side circuit (412) is received from a pressure sensor (426) upstream of the relief valve (408).

6. 2. The control system (101) of claim 1, further comprising a transmitter (124) in communication with the controller (120), wherein the tool data is received by the controller (120) from a transmitter (124) mounted on the work tool (116).

7. The control system (101) of claim 4, wherein the opening of the relief valve (408) drains hydraulic fluid from the work tool (116) to the reservoir (404).

8. 1. A method for reducing pressure in a work tool auxiliary circuit (400) in fluid communication with a work tool (116) coupled to a work machine (100) by a quick coupler (114), the work tool (116) comprising a work tool valve block (302), the quick coupler (114) comprising a quick coupler valve block (300) and a locking member (306) movable between a locked position (310) and an unlocked position (308), the work tool auxiliary circuit (400) comprising a reservoir (404) and a first relief valve (408) in fluid communication with the quick coupler valve block (300) and the reservoir (404), the method comprising: receiving an unlock signal for the work tool (116); receiving tool data associated with the work tool (116), the tool data including a target pressure for the work tool auxiliary circuit (400) or an open time for the first relief valve (408); automatically actuating, in response to the unlock signal and the tool data, by a controller (120) to open the first relief valve (408) (a) during the open time, or (b) until the target pressure is reached in the work tool auxiliary circuit (400) or machine-side circuit (412), or (c) to reach and maintain the target pressure in the work tool auxiliary circuit (400) or machine-side circuit (412); and moving the locking member (306) to the unlocked position (308).

9. The method of claim 8, wherein the first relief valve (408) is a solenoid pressure release valve.

10. 9. The method of claim 8, wherein the automatically actuating the opening of the first relief valve (408) occurs until the target pressure is reached in the work tool auxiliary circuit (400).

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