Hydraulic oscillation mitigation system for a work machine

Abstract

A hydraulic system for controlling a hydraulic circuit of a work machine is disclosed. The hydraulic system can include a first hydraulic cylinder assembly, a second hydraulic cylinder assembly, a third hydraulic cylinder assembly, and a valve. The third hydraulic cylinder assembly, when coupled to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, can be configured to control a flow of hydraulic fluid between the first hydraulic cylinder assembly and the second hydraulic cylinder assembly to limit a range of travel of the first piston and a range of travel of the second piston.

Description

Technical Field

[0001] This application generally relates to (but is not limiting) a hydraulic system for a working machine, and more specifically to a hydraulic vibration mitigation system for a rotary mixer machine or a cold planer machine, which can be used to remove or recycle paved surfaces. Background Technology

[0002] Rotary mixer machines and cold planer machines can be used to mill or grind old or degraded pavement from surfaces such as highways and parking lots. A cold planer can be configured to remove the pavement from the surface for transport, while a rotary mixer can be configured to rebuild or recycle the pavement for reuse on the surface. These surfaces can extend over uneven terrain. Thus, these machines can include systems for adjusting the machine's vertical height and rotary cutting tools attached thereto, to control, for example, the cutting depth and provide a smooth ride for the operator.

[0003] Suspension systems for ride control have been developed. U.S. Patent No. 6,308,973 to Griebel et al., entitled “Suspension System with Axle Oscillation Circuit,” is an example of such a suspension system. Attached Figure Description

[0004] Figure 1 This is a schematic side view of an example of a working machine according to this application, the working machine comprising a rotary mixer having multiple transport devices mounted to a lifting column.

[0005] Figure 2 This is a schematic diagram of a system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to a first hydraulic system.

[0006] Figure 3 This is a schematic diagram of a second system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to a second hydraulic system.

[0007] Figure 4 This is a schematic diagram of a third system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to a third hydraulic system.

[0008] Figure 5 This is a schematic diagram of a fourth system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to a fourth hydraulic system.

[0009] Figure 6This is a schematic diagram of a fifth system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to a fifth hydraulic system.

[0010] Figure 7 This is a schematic diagram of a sixth system comprising two transport devices according to an example of this application, each transport device being connected to one of the lifting columns, which are operatively connected to the sixth hydraulic system.

[0011] Figures 8A-8D Various alternative configurations of the third hydraulic cylinder assembly according to examples of this application are shown. Summary of the Invention

[0012] In one example, a hydraulic system for controlling a hydraulic circuit of a working machine is disclosed. The hydraulic system may optionally include a first hydraulic cylinder assembly, a second hydraulic cylinder assembly, a third hydraulic cylinder assembly, and a valve. The first hydraulic cylinder assembly may have a first piston and a first rod for coupling to a first thruster of the working machine. The second hydraulic cylinder assembly may have a second piston and a second rod for coupling to a second thruster of the working machine. The third hydraulic cylinder assembly may have at least one third piston. The first valve is configurable to selectively fluidly connect the third hydraulic cylinder assembly to the first and second hydraulic cylinder assemblies. When connected to the first and second hydraulic cylinder assemblies, the third hydraulic cylinder assembly may be configured to control the flow of hydraulic fluid between the first and second hydraulic cylinder assemblies to limit the range of travel of the first and second pistons.

[0013] In another example, a working machine comprising either a rotary mixer or a cold planer is disclosed. The working machine may optionally include a frame, a rotor, a propulsion system, a first leg, a second leg, and a hydraulic system. The rotor may be coupled to the frame and can be configured to rotate relative to it. The propulsion system may include a plurality of thrusters, which may be configured to move the working machine. The first leg may be coupled to the frame and has a first hydraulic cylinder assembly as part thereof. The first leg may be configured via the first hydraulic cylinder assembly to lift the frame relative to the first thruster. The second leg may be coupled to the frame and may have a second hydraulic cylinder assembly as part thereof. The second leg may be configured via the second hydraulic cylinder assembly to lift the frame relative to the second thruster. The hydraulic system may include a first hydraulic cylinder assembly having a first piston and a second hydraulic cylinder assembly having a second piston. The hydraulic system may further optionally include a flow control device and a first valve configured to selectively fluidly connect the third hydraulic cylinder assembly to the first and second hydraulic cylinder assemblies. When connected to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, the flow control device can be configured to control the flow of hydraulic fluid between the first hydraulic cylinder assembly and the second hydraulic cylinder assembly to limit the travel range of the first piston and the second piston. Detailed Implementation

[0014] The following description, set forth in conjunction with the accompanying drawings, is intended as a description of various embodiments of the described subject matter and is not necessarily intended to represent the only embodiment. In some cases, the description includes specific details to provide an understanding of the described subject matter. However, it will be apparent to those skilled in the art that embodiments can be practiced without these specific details. In some instances, well-known structures and components may be shown in block diagram form to avoid obscuring the concept of the described subject matter. Throughout the drawings, the same reference numerals are used wherever possible to denote the same or similar components.

[0015] Any reference to "an embodiment," "embodiment," "example," or "a single example" in the specification means that a particular feature, structure, characteristic, operation, or function described in connection with an embodiment is included in at least one embodiment. Therefore, any appearance of the above phrases in the specification does not necessarily refer to the same embodiment. Furthermore, particular features, structures, characteristics, operations, or functions may be combined in any suitable manner in one or more embodiments, and it is intended that embodiments of the described subject matter may and do indeed cover modifications and variations of the described embodiments.

[0016] It must also be noted that, as used in the specification, appended claims, and abstract, the singular forms “a,” “an,” and “the” include plural indicators unless the context clearly indicates otherwise. That is, unless explicitly stated otherwise, as used herein, the words “a” and “an,” etc., have the meaning of “one or more.” Furthermore, it should be understood that terms such as “left,” “right,” “top,” “bottom,” “front,” “back,” “side,” “height,” “length,” “width,” “up,” “down,” “inner,” “outer,” “next,” “inner,” and “outer” that may be used herein describe reference points only and do not necessarily limit embodiments of the described subject matter to any particular orientation or configuration. Moreover, terms such as “first,” “second,” and “third” identify only one of the various parts, components, reference points, operations, and / or functions described herein, and similarly do not necessarily limit embodiments of the described subject matter to any particular configuration or orientation.

[0017] The terms “basically,” “about,” “generally,” or variations thereof shall be understood to mean within ±10% or ±10 degrees of the provided value, whatever applies.

[0018] Figure 1 This is a schematic side view of a working machine 100 including a rotary mixer 102, according to an example of the present invention. It should be understood that embodiments of the invention can be similarly applied to other types of machines, such as, but not limited to, road milling machines, road recycling machines, cold planers, etc. Similarly, the application of such machines is not limited to road recycling or road milling.

[0019] according to Figure 1 As an example, the rotary mixer 102 includes a frame 104 and a cab 106 mounted on the frame 104. The cab 106 may include control elements for controlling various operations of the rotary mixer 102.

[0020] The frame 104 can also be connected to the drivetrain 108 (e.g., a gearbox, shaft, power source 110, etc.). The power source 110 may include an internal combustion engine, an electric motor, a generator, a power storage device including a battery, a hybrid engine, or a combination of two or more of the aforementioned power sources.

[0021] Machine 100 may have a transport device 112, which, as described below, may include wheels, tracks, or other movable ground engagement devices. Therefore, in some embodiments, transport device 112 may include metal link tracks, rubber tracks, pneumatic tires, pneumatic rubber tires, hard tires, etc. Each transport device 112 may be connected to frame 104 via a corresponding one of a plurality of lifting columns 114. Transport devices 112 may be configured to support frame 104 on ground 118 and also facilitate the propulsion of rotary mixer 102 on ground 118 in a desired direction and at a desired speed.

[0022] The frame 104 can extend longitudinally along frame axis A between a first (front) end and a second (rear) end. A rotor assembly 120, including a portion of the milling system 122, can be coupled, for example, to the underside of the frame 104. The rotor assembly 120 and the milling system 122 can be movable relative to the frame 104 and the ground 118, or in some cases, fixed relative to the frame 104. Other components of the rotor assembly 120 and the milling system 122 can be driven to move by a drivetrain 108 and can be configured to selectively engage the ground 118 for milling, recycling, etc.

[0023] The frame 104 can be supported by the transport device 112 via lifting columns 114. The lifting columns 114 (also referred to herein as outriggers) can be configured to raise and lower the frame 104 relative to the transport device 112 and the ground 118. One or more lifting columns 114 can be configured to rotate along a vertical axis (e.g., perpendicular to axis A) to provide steering for the rotary mixer 102.

[0024] The rotary mixer 102 may include four independent conveying devices 112: a front left conveyor, a front right conveyor, a rear left conveyor, and a rear right conveyor, each of which can be connected to one of the lifting columns 114. That is, it can be... Figure 1 Further entry near the propulsion device 112 shown Figure 1 Additional propulsion devices 112 and lifting columns 114 are provided within the plane. The invention is not limited to any particular number of propulsion devices or lifting columns.

[0025] A lifting column 114 can be provided to raise and lower the frame 104 to, for example, control the cutting depth of the rotor assembly 120 and accommodate the rotary mixer 102 engaging obstacles on the ground. As described herein, the lifting column 114 and other components of the machine 100 can be coupled to a control system, as referenced in [reference needed]. Figure 3-6 Further discussion is needed.

[0026] The rotary mixer 102 may further include a rotor assembly 120 and a milling system 122. These may be connected to the frame 104. The milling system 122 may include the rotor assembly 120 operatively connected to a power source 110 for rotation. The rotor assembly 120 may include milling rollers, cutting rollers, planing rollers, mixing rollers, etc. The rotor assembly 120 may include a plurality of cutting tools, such as chisels, arranged thereon. The rotor assembly 120 is rotatable about a roller or housing axis and extends in a direction perpendicular to the frame axis A. Figure 1 In the plane of the surface. As the rotor assembly 120 swirls or rotates about the roller axis, the cutting tool can engage the ground 118, which may include, for example, the surface, dirt, asphalt, or concrete of an existing work area, road, bridge, parking lot, etc. Furthermore, when the cutting tool engages the ground 118, it engages layers of material forming the ground 118, such as hardened dirt, rock, or pavement, and moves these layers to remove or mix them. The swirl motion of the rotor assembly 120 and the cutting tool then transports the material of the ground 118 through a mixing chamber 124 for redeposition on the ground. The mixing chamber 124 may be defined by a plurality of plates positioned around the rotor assembly 120.

[0027] In other words, the rotor assembly 118 can be configured to selectively contact the ground 118 during machine travel to recycle and / or pulverize the ground 118, for example by mixing the recycled soil or paving material with various additives or aggregates deposited on the working surface. Therefore, the rotary mixer 102 of this application can include a system for depositing additives such as silicate cement, lime, fly ash, cement kiln dust, etc., on the working surface during recycling or pulverizing operations.

[0028] During movement on the ground 118, or when the rotor assembly 120 engages the ground 118 in milling operation mode, or when the rotor assembly 120 retracts in transport or riding operation mode, the transport device 112 may experience different terrains such as slopes, valleys, depressions, etc. When the hydraulic system operates to redistribute the hydraulic fluid within the system to each cylinder, balance the load, and keep the frame 104 slightly level, such terrain may cause one or more rods or pistons of the lift column 114 to be pushed inward into the cylinder of the lift column 114 and / or extend further outward from the cylinder relative to each other.

[0029] Figure 2 An example of a hydraulic system 200 for traversing terrain including a slope 202 is provided. The hydraulic system 200 may include a first hydraulic cylinder assembly 204 (sometimes referred to herein as a first hydraulic unit) and a second hydraulic cylinder assembly 206 (sometimes referred to herein as a second hydraulic unit). The first hydraulic cylinder assembly 204 may include a cylinder 208A, a piston 210A, and a rod 212A. The second hydraulic cylinder assembly 206 may include a cylinder 208B, a piston 210B, and a rod 212B.

[0030] The first hydraulic cylinder assembly 204 may be fluidly connected to the second hydraulic cylinder assembly 206, for example, via one or more fluid lines 220A and 220B. The first hydraulic cylinder assembly 204 may be... Figure 1 It is part of one of the lifting columns 114. Similarly, the second hydraulic cylinder assembly 206 may be... Figure 1 It is part of another lifting column 114. It is conceivable that the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206 could be... Figure 1 It is part of any combination of lifting posts 114. Therefore, they can be, for example, two of the following: a rear lifting post, two front lifting posts, two left lifting posts, or two right lifting posts.

[0031] Figure 2 The schematic diagram shows that rod 212A can be connected to a previously... Figure 1 The first propulsion device 112A is shown among the plurality of propulsion devices 112. Similarly, rod 212B can be connected to a second propulsion device 112B of the plurality of propulsion devices 112. Rods 212A and 212B can extend from corresponding cylinders in cylinders 208A and 208B, and can extend to connect with corresponding propulsion devices in propulsion devices 112. It should be noted that rods 212A and 212B may not be directly connected to the corresponding first and second propulsion devices 112A, 112B, but may be indirectly connected to them via other components of the lifting column not specifically shown. Therefore, in Figure 2 The connection between rods 212A and 212B and the corresponding first and second propulsion devices 112A and 112B has been simplified.

[0032] Both the first and second hydraulic cylinder assemblies 204 and 206 can be designed as double-acting cylinders. Thus, each has a piston-side first chamber 216, 218 and a piston rod-side second chamber 218, 218, respectively. These chambers 216, 218 can be separated from each other by corresponding pistons 210A, 210B located in corresponding cylinders 208A, 208B. The first and second chambers 216, 218 can be filled with a pressure medium, which can be, for example, a hydraulic fluid, such as, but not limited to, oil. Filling these first chambers or emptying the second chamber can cause the frame to descend or rise from the ground.

[0033] The first and second hydraulic cylinder assemblies 204 and 206 are fluidly connected to each other via fluid lines 220A and 220B. Alternatively, the first and second hydraulic cylinder assemblies 204 and 206 may be fluidly connected to each other via a raise / lower valve. The raise / lower valve is described and illustrated with reference to the following figures. Fluid lines 220A and 220B allow power to be transmitted from the first hydraulic cylinder assembly 204 to the second hydraulic cylinder assembly 206 by maintaining a pressurized engagement.

[0034] Figure 2 The diagram illustrates the machine operating on ramp 202 (in drive or milling mode). This configuration causes the rod 212A and piston 210A of the first hydraulic cylinder assembly 204 to be pushed inward toward the frame into cylinder 208A relative to the rod 212B and piston 210B of the second hydraulic cylinder assembly 206. In other words, the rod 212B and piston 210B can extend further outward from cylinder 208B toward the ground (here, ramp 202) relative to the rod 212A and piston 210A of the first hydraulic cylinder assembly 204. Figure 2 The diagram shows rod 212A and piston 210A near their full displacement positions relative to cylinder 208A, and rod 212B and piston 210B in their full displacement positions relative to cylinder 208B. Each of the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206 may have two full displacement positions, one where the piston and rod are retracted and the other where the piston and rod are extended.

[0035] In extreme cases, for example Figure 2 In extreme cases, rods 212A, 212B and pistons 210A, 210B move / oscillate toward their full displacement positions (also referred to herein as full range positions, full stroke positions, full travel positions, end-of-stroke positions, or full-stroke positions). As used herein, the term "oscillate" or "oscillation" refers to the total movement of the piston and rod of one hydraulic cylinder assembly relative to the cylinder of that assembly, or the total movement of the piston and rod of one hydraulic cylinder assembly relative to the piston and rod of another hydraulic cylinder assembly. Figure 2 The movement shown can prevent or reduce unintended frame loads and / or maintain the frame level for operator comfort. However, if the movement / oscillation is inherently too extreme (i.e., one or more levers and pistons move to their fully displaced positions), this can result in undesirable frame loads. For example, such undesirable frame loads may make it difficult to maintain the desired inclination of the machine. It should be noted that levers 212A, 212B and pistons 210A, 210B can move / oscillate to their fully displaced positions as a result of factors other than terrain, such as obstacles or operator-induced criteria (e.g., the desire to mill at an inclination or slant). Therefore, in some cases, a fully displaced position does not necessarily have to be a result of terrain. In fact, recognizing that this device, system, and method helps prevent unintended frame loads and makes the machine more stable. This should be contrasted with the system and method in co-pending U.S. Application Serial No. 16 / 658,996, entitled “Ride control system and method for a rotary cutter,” filed October 21, 2019, the entire specification of which is incorporated herein by reference, and addresses machine vibration.

[0036] This application relates to devices, systems, and methods for monitoring and controlling the movement of pistons 210A, 210B and rods 212A, 212B, in order to, for example, help prevent unintentional frame loads and, as a result of the hydraulic system, make the machine more stable while maintaining the frame 104 ( Figure 1 The orientation of the rotor assembly 120 is maintained, and the rotor assembly 120 is kept in the correct orientation. Figure 1 The required cutting characteristics of ). Specifically, the present invention provides, as in Figure 3-6 Various examples further illustrated herein can utilize valves and third hydraulic cylinder assemblies (sometimes referred to herein as flow control devices, third hydraulic units, or intermediate elements). The third hydraulic cylinder assembly may include, for example, a free-floating piston, a piston and rod assembly, a gas compression piston, and / or a dual-diameter cylinder assembly. The third hydraulic cylinder assembly may operate automatically to a controller or may operate in conjunction with a controller, such as… Figure 6 The description further explains how to limit the travel range of the piston and rod within the cylinders of the first and second hydraulic cylinder assemblies, respectively. This limitation on the travel range of the piston and rod can hold them in a desired position, such as substantially full displacement, full displacement, or a position less than full displacement (e.g., between 85% and 99.9% of full displacement) or another position.

[0037] Figure 3 This is a schematic diagram of a second embodiment of the hydraulic system 300. In addition to the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206, which are part of and connected to the respective lifting columns as shown and described above, the system 300 includes conveying devices 112A and 112B, valve 302, third hydraulic cylinder assembly 304, and raise / lower valve 306.

[0038] The configuration of the first and second hydraulic cylinder assemblies 204 and 206 has been previously described. The first hydraulic cylinder assembly 204 can be selectively fluidly coupled / connected to the second hydraulic cylinder assembly 206 via valve 302. Valve 302 can be positioned between the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206 and can be fluidly communicated with it via fluid lines 308A and 308B.

[0039] According to one example, valve 302 may comprise a proportional four-way two-position valve. Valve 302 may include a flow control device configured to directly or indirectly fluidly connect a first hydraulic cylinder assembly 204 to a second hydraulic cylinder assembly 206, and fluidly connect a third hydraulic cylinder assembly 304 to the first and second hydraulic cylinder assemblies 204 and 206, as further described herein.

[0040] According to one operating mode or setting, valve 302 can be configured in a first setting to allow direct communication between the first and second hydraulic cylinder assemblies 204 and 206 via lines 308A and 308B. This configuration can be performed / used in conjunction with a raise / lower valve 306 that is actuated to open to allow hydraulic fluid to flow to the first and second hydraulic cylinder assemblies 204 and 206 to perform, for example, raising and / or lowering the frame of a work machine.

[0041] Valve 302 can also be fluidly connected to the third hydraulic cylinder assembly 304 via fluid lines 310A and 310B. Valve 302 can be configured to be in a second setting or operating mode to allow indirect communication between the first and second hydraulic cylinder assemblies 204 and 206 and the third hydraulic cylinder assembly 304 via lines 310A and 310B. For example, this configuration can be performed / used when the raise / lower valve 306 is actuated to be closed.

[0042] The third hydraulic cylinder assembly 304 can be constructed in a similar manner to the aforementioned first hydraulic cylinder assembly 204 and second hydraulic cylinder assembly 206. However, as Figure 3 As shown, the third hydraulic cylinder assembly 304 can be different; for example, it can be rodless and can have a floating piston 312.

[0043] The third hydraulic cylinder assembly 304 may include cylinders other than piston 312. Piston 312 divides the third hydraulic cylinder assembly 304 into a first chamber 314 in fluid communication with line 310A and a second chamber 316 in fluid communication with line 310B. These chambers 314 and 316 may be configured similarly to those previously described with respect to the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206. The volumes of chamber 314 and chamber 316 may be configured to control / limit the degree or range of travel of pistons 210A, 210B and rods 212A, 212B. In other words, the third hydraulic cylinder assembly 304 may be configured to control the flow of hydraulic fluid between the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206 to limit the range of travel of the first piston 210A and the second piston 210B within the respective cylinders 208A and 208B. In this manner, the third hydraulic cylinder assembly 304 can be used to restrict / control the pistons 210A, 210B and rods 212A, 212B to substantially full displacement or another desired position. For example, such a desired position could be full displacement, less than full displacement (e.g., between 85% and 99.9% of full displacement), or another position. As previously stated, the hydraulic cylinder assembly 304 can be used conditionally, for example, only after the raise / lower valve 306 has closed.

[0044] Fluid lines 320 are fluidly connected to a first hydraulic cylinder assembly 204 and a second hydraulic cylinder assembly 206, and fluid lines 322A and 322B are fluidly connected to a valve 306 and at least the first hydraulic cylinder assembly 204. It should be noted that in situations such as... Figure 7 In an alternative example of the illustrated example, fluid line 320 may be removed, and the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206 may be fluidly connected at the raise / lower valve 306 (or a port of a tank fluidly connected to the raise / lower valve 306). System 300 may include a closed system comprising fluid lines, valves 302, 306, and the first, second, and third hydraulic cylinder assemblies 204, 206, and 304. It should be noted that, for example, although a single raise / lower valve 306 is shown connected in series with the first, second, and third hydraulic cylinder assemblies 204, 206, and 304, it is conceivable that multiple raise / lower valves may be utilized according to some examples. For example, one embodiment may have a raise / lower valve for each lifting column (e.g., one for the first hydraulic cylinder assembly 204 and another for the second hydraulic cylinder assembly 206). One such embodiment is described herein as... Figure 7 As shown.

[0045] Figure 4 This is a schematic diagram of a third embodiment of the hydraulic system 400. The hydraulic system 400 can be connected with... Figure 3 The hydraulic system 300 is substantially similar to or identical to the hydraulic system 400, except that the third hydraulic cylinder assembly 404 of the system 400 can be configured to include a first rod 403A and a second rod 403B. Therefore, unlike the third hydraulic cylinder assembly 304 which uses a floating piston 312, the piston 412 of the third hydraulic cylinder assembly 404 can be coupled to the first rod 403A on its first side and the second rod 403B on its second side. Rods 403A and 403B can extend outward from the cylinder of the third hydraulic cylinder assembly 404, such as... Figure 4 As shown. According to some examples, the first rod 403A may have a different diameter and / or shape than the second rod 403B. For example, this configuration can bias the third hydraulic cylinder assembly 404 and the system 400 in a desired manner to affect the travel of the piston of one of the first hydraulic cylinder assemblies 204 relative to the piston of the second hydraulic cylinder assembly 206.

[0046] Figure 5 This is a schematic diagram of a fourth embodiment of the hydraulic system 500. The hydraulic system 500 can be connected with... Figure 3The hydraulic system 300 is substantially similar or identical to that of the hydraulic system 300, except that system 500 may include a second valve 502 configured to selectively fluidly communicate hydraulic fluid with the third hydraulic cylinder assembly 304. System 500 may also include fluid lines 504A and 504B as additional features. Fluid line 504A may be in fluid communication with the volumetric fluid of chamber 314 and fluid line 504B may be in fluid communication with the volumetric fluid of chamber 316.

[0047] Valve 502 may include a proportional four-way three-position valve. Valve 502 may include a flow control device configured to selectively open and close to fluidly connect the third hydraulic cylinder assembly 306 to a reservoir and source (denoted as pressure source "P" and tank "T") via fluid lines 504A and 504B.

[0048] Valve 502 can be configured to selectively open and / or close to pressurize chamber 314 or chamber 316 relative to one of them, thereby adjusting the positioning of the floating piston 312. Alternatively or additionally, a proportional pressure reducing valve (not shown) may be used to center the floating piston 312 based on the pressure in the cylinders of the first hydraulic cylinder assembly 204 and the second hydraulic cylinder assembly 206. This adjustment can be used to zero or reposition the piston 312 as needed. Although shown with a floating piston 312, in some embodiments, Figure 5 The configuration can also be used with a rod that is part of a third hydraulic cylinder assembly. Figure 4 Used together with the system.

[0049] One can imagine, for example Figure 3-5 The embodiments can be operated passively without requiring active control to limit the travel of the piston in one of the first hydraulic cylinder assemblies 204 and the piston in the second hydraulic cylinder assembly 206 as described above. However, using, for example... Figure 6 The active control of the controller described herein is also considered for use with any disclosed embodiments.

[0050] Figure 6 This is a schematic diagram of a fifth embodiment of the hydraulic system 600. The hydraulic system 600 can be connected with... Figure 5 The hydraulic system 500 is substantially similar or identical to the hydraulic system 600, except that system 600 may additionally include a controller 602 and a sensor 604. The controller 602 may communicate electronically with the sensor 604. In addition, the controller 602 may communicate electronically with valves 502, 302 and / or 306 to selectively open or close valves 502, 302 and / or 306 as described above.

[0051] According to one example, sensor 604 can be configured as a position sensor to sense the position of piston 312 within the cylinder of third hydraulic cylinder assembly 304. Controller 602 can be configured to selectively operate second valve 502 based on input from sensor 604 (e.g., position data) to change the position of piston 312 within third hydraulic cylinder assembly 304. This scheme allows piston 312 to be repositioned within the cylinder of third hydraulic cylinder assembly 304 to achieve a zero position as shown or another desired position.

[0052] The controller 602 may include one or more processors, microprocessors, microcontrollers, electronic control modules (ECMs), electronic control units (ECUs), programmable logic controllers (PLCs), or any other suitable device for electronic control functions.

[0053] The controller 602 can be configured to operate according to a predetermined algorithm or instruction set for controlling at least some functions of the machine 10, such as those described above. Such an algorithm or instruction set can be stored in a database, read into the on-board memory of the controller 602, or pre-programmed onto a storage medium or memory accessible by the controller 602, for example in the form of a floppy disk, hard disk, optical media, random access memory (RAM), read-only memory (ROM), or any other suitable computer-readable storage medium commonly used in the art (each referred to as a "database"), which can be in the form of a physical, non-transitory storage medium.

[0054] According to some examples, controller 602 can communicate electronically with various other components, systems, or subsystems of machine 10 (such as drive systems). Thus, according to such examples, controller 602 can communicate electronically with various controllers, systems, and components (e.g., engines, hydraulic motors, hydraulic systems, etc., including those previously discussed). Through this electronic communication, controller 602 can receive data relating to the current operating parameters of machine 10 from sensors such as position sensor 604 of system 600. In response to such input, controller 602 can perform various determinations and transmit output signals corresponding to the results of such determinations or to actions that need to be performed, such as for repositioning piston 312 as previously described.

[0055] Figure 7 This is a schematic diagram of the sixth embodiment of the hydraulic system 700. The hydraulic system 700 can be connected with... Figure 5 and Figure 6Hydraulic systems 500 and 600 are substantially similar or identical, except that system 700 may include two second valves 702A and 702B configured to independently and selectively fluidly communicate hydraulic fluid with the third hydraulic cylinder assembly 704. System 700 may also include separate raise / lower valves 706A and 706B. Fluid line 708A may be in fluid communication with the volumetric fluid of chamber 714 of the third hydraulic cylinder assembly 704, and fluid line 708B may be in fluid communication with the volumetric fluid of chamber 716. These valves 702A and 702B can regulate the hydraulic fluid communication along their respective fluid lines 708A and 708B.

[0056] Figure 7 The system 700 is shown to have one raise / lower valve 706A, 708B for each lifting column (e.g., one raise / lower valve 706A is fluidly connected to a first hydraulic cylinder assembly 204, while the other raise / lower valve 706B is fluidly connected to a second hydraulic cylinder assembly 206). Raise / lower valves 706A and 706B may both be connected to the same hydraulic tank (not shown), or, for example, different hydraulic tanks.

[0057] Using the hydraulic system 700, one or both sides of the system 700 can be commanded to allow hydraulic fluid to flow independently of the other side, regardless of whether the third hydraulic cylinder assembly 704 is activated and used. For example, the raise / lower valve 706A can be selectively opened to move the piston and rod within the first hydraulic cylinder assembly 204, while the second raise / lower valve 706B can remain closed. During this process, the second valve 702A can remain closed.

[0058] Figures 8A-8D Another alternative configuration of the third hydraulic cylinder assembly is shown. These embodiments illustrate one or more springs that can be used to recenter the piston of the third hydraulic cylinder assembly when the machine returns to a generally flat surface.

[0059] Figure 8AA third hydraulic cylinder assembly 804 is shown, comprising a cylinder 805, a piston 806, a rod 808, and a first spring 810A and a second spring 810B. The third hydraulic cylinder assembly 804 can be constructed as described above, wherein the piston 806 is positioned within and movable relative to the cylinder 705. The rod 808 can be connected to the piston 806 and can extend from the cylinder 805. The first spring 810A can be connected to the piston 806 and can extend around or adjacent to the rod 808 within the cylinder 805. The first spring 810A can contact the inner end of the cylinder 812A. The second spring 810B can be connected to one outer end of the cylinder 812A and can be connected to a flange 812 or other feature of the rod 808 or to another component not specifically shown. The second spring 810B can extend around or adjacent to the rod 808.

[0060] Figure 8B A third hydraulic cylinder assembly 904 is shown, comprising a cylinder 905, a piston 906, and springs 910A and 910B. A rod cannot be used in this embodiment. The third hydraulic cylinder assembly 904 can be constructed as described above, wherein the piston 906 is positioned within the cylinder 905 and is movable relative to the cylinder 905. Spring 910A may be connected to the piston 906 at a first end and may extend to contact a first end 912A of the cylinder 905. Spring 910B may be connected to the piston 906 at a first end and may extend to contact a second end 912B of the cylinder 905. The first end 912A of the cylinder 905 may be opposite the second end 912B of the cylinder 905.

[0061] Figure 8C The third hydraulic cylinder assembly 1004 is shown, which has a cylinder 1005, a piston 1006, rods 1008A and 1008B, and springs 1010A and 1010B. Figure 8C The example differs from the previous embodiment in that the two rods 1008A and 1008B are used in conjunction with two springs 1010A and 1010B. Springs 1010A and 1010B may be external to cylinder 1005. Spring 1010A may be connected to a first end 1012A of cylinder 1005 and may extend around or adjacent to rod 1008A. Spring 1010A may be connected to flange 1014A or other features of rod 1008A or connected to another component not specifically shown. Similarly, spring 1010B may be connected to a second end 1012B of cylinder 1005 and may extend around or adjacent to rod 1008B. Spring 1010B may be connected to flange 1014B or other features of rod 1008B or connected to another component not specifically shown.

[0062] Figure 8D It shows the relationship with Figure 8CThe third hydraulic cylinder assembly 1004 is similar to the third hydraulic cylinder assembly 1104. The difference between the third hydraulic cylinder assembly 1104 and the third hydraulic cylinder assembly 1004 is that... Figure 8B The arrangement is similar to that described in the text, with springs 1110A and 1110B inside cylinder 1105.

[0063] Industrial applicability

[0064] This application describes various devices, systems, and methods for controlling the movement of a machine frame relative to a propulsion element or transport device. These propulsion elements or transport devices can be mounted to lifting legs including hydraulic cylinders, which can be controlled using the hydraulic systems disclosed herein. For example, the hydraulic system can include at least two hydraulic cylinder assemblies capable of fluidly coupling to each other, for example, in a closed-loop manner. The system may have a third hydraulic cylinder assembly fluidly coupled to the first and second hydraulic cylinder assemblies. As previously described, the third hydraulic cylinder assembly can be configured to control the flow of hydraulic fluid between the first and second hydraulic cylinder assemblies to limit the range of travel of the first piston of the first hydraulic cylinder assembly and the second piston of the second hydraulic cylinder assembly. In this way, the third hydraulic cylinder assembly can be used to limit / control the movement / displacement of the first and second pistons (and additionally rods connected thereto). The third hydraulic cylinder assembly can be used to achieve a desired maximum displacement position of the first piston and the second position. This desired maximum displacement position can be selected to reduce or eliminate undesirable frame loads, which can be caused by the operation of the hydraulic system lifting the frame when the first and / or second pistons move to their full stroke / displacement positions. This undesirable frame load can make it difficult to maintain the desired inclination of the machine. In other words, a third hydraulic cylinder assembly can be used to allow some movement in the first and second hydraulic assemblies. This movement is sufficient to prevent frame twisting. The dimensions (volume) of the third hydraulic cylinder assembly can be set to limit the travel of the pistons and rods of the first and second hydraulic assemblies. By limiting the travel, the amount of distance the working machine can move left and right can be limited. Therefore, the system discussed in this paper helps maintain the stability level of the working machine.

[0065] The difference between this system and method and suspension systems for ride control, such as those in U.S. Patent No. 6,308,973 to Griebel et al. and co-pending U.S. Patent Application Serial No. 16 / 658,996, is that this system and method focuses not on vibration damping, but on limiting total piston travel / displacement that would result in unintended frame loads, as discussed further herein.

Claims

1. A hydraulic system for controlling a hydraulic circuit of a working machine, the hydraulic system comprising: A first hydraulic cylinder assembly, the first hydraulic cylinder assembly having a first piston and a first rod for coupling to a first thruster of the working machine; A second hydraulic cylinder assembly having a second piston and a second rod for coupling to a second thruster of the working machine; A third hydraulic cylinder assembly having at least a third piston; A first valve is configured to selectively fluidly connect the third hydraulic cylinder assembly to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, wherein when connected to the first hydraulic cylinder assembly and the second hydraulic cylinder assembly, the third hydraulic cylinder assembly is configured to control the flow of hydraulic fluid between the first hydraulic cylinder assembly and the second hydraulic cylinder assembly to limit the travel range of the first piston and the travel range of the second piston.

2. The hydraulic system of claim 1, wherein the third hydraulic cylinder assembly further includes a first rod connected to a first side of the third piston and a second rod connected to a second side of the piston, and wherein the third hydraulic cylinder assembly further includes one or more springs configured to reposition the third piston of the third hydraulic cylinder assembly.

3. The hydraulic system according to any one of claims 1-2, further comprising a second valve configured to regulate the hydraulic fluid to the third hydraulic cylinder assembly to change the position of the third piston.

4. The hydraulic system of claim 3, further comprising: a sensor for sensing the position of the third piston within the third hydraulic cylinder assembly; and a controller configured to selectively operate the second valve based on input from the sensor to change the position of the third piston within the third hydraulic cylinder assembly.

5. The hydraulic system of claim 4, wherein the controller is configured to selectively operate the first valve.

6. The hydraulic system according to any one of claims 1-2, wherein the third piston is a piston that floats freely within the third hydraulic cylinder assembly, having one or more rods connected thereto, or having one or more springs engaged thereto.

7. The hydraulic system according to any one of claims 1-2, further comprising: The frame of the machine in operation; A first leg, the first leg being coupled to the frame and having a first hydraulic cylinder assembly as part thereof, wherein the first leg is configured via the first hydraulic cylinder assembly to lift the frame relative to the first thruster; and A second leg, which is coupled to the frame and has a second hydraulic cylinder assembly as part thereof, wherein the second leg is configured via the second hydraulic cylinder assembly to lift the frame relative to the second thruster.

8. The hydraulic system according to any one of claims 1 to 2, wherein the working machine comprises one of a cold planer or a rotary mixer.

9. A method for controlling movement between adjacent hydraulic devices in a hydraulic circuit of a working machine, the method comprising: Provide or obtain a first hydraulic device and a second hydraulic device, wherein the first hydraulic device is coupled to a first thruster and configured to lift the frame of the working machine relative to the first thruster, and wherein the second hydraulic device is coupled to a second thruster and configured to lift the frame of the working machine relative to the second thruster; Selectively fluidly connect a third hydraulic device to the first and second hydraulic devices; and When a third hydraulic device is fluidly connected to the first hydraulic device and the second hydraulic device, the third hydraulic device is used to limit the travel range of the first piston of the first hydraulic device and the travel range of the second piston of the second hydraulic device.

10. The method of claim 9, wherein the third hydraulic device comprises a hydraulic cylinder assembly having a piston, the piston being one of being freely floating within the cylinder of the hydraulic cylinder assembly, connected to a first rod, or engaged by a spring.

11. The method of claim 10, further comprising adjusting hydraulic fluid to the hydraulic cylinder assembly to change the position of the piston or biasing at least one of the pistons with the spring.

12. The method of claim 11, further comprising: Sensing the position of the piston in the cylinder; and The position of the piston is sensed to control the adjustment of the hydraulic fluid to the hydraulic cylinder assembly, thereby changing the position of the piston.

13. The method according to any one of claims 9-12, wherein the first, second and third hydraulic devices each comprise a hydraulic cylinder assembly and each has at least a piston located within the cylinder, wherein the third hydraulic device is selectively fluidly connected between the first hydraulic device and the second hydraulic device, and wherein the piston of the third hydraulic device moves from relatively close to the first hydraulic device to relatively close to the second hydraulic device in response to a change in the position of the piston of the first hydraulic device relative to the position of the piston of the second hydraulic device.

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