Patent Application
20240410399
Embodiments of the present invention are directed generally to systems and methods for selectively amplifying power to a hydraulic working cylinder. Embodiments of the present invention are particularly useful for providing supplemental breakout force to working cylinders on loader equipment, such as bucket loaders.
Hydraulic cylinders are commonly used on many types of heavy-equipment machines and/or agricultural equipment. For example, a hydraulic assembly comprising one or more hydraulic cylinders may be used on loader so as to raise and lower arms and/or rotate or otherwise move a loader attachment, such as a bucket attachment. Loaders on construction equipment have limitations on the force available for use to curl-back (pry) with a bucket attachment. The reason for these limitations is based on the geometry of the loader dictating that the rod end of the working (bucket) cylinder is used to curl the bucket back. Linkages like the Z-bar linkages have been used to address this problem. However, for some machines, these linkages hinder cab accessibility, reduce visibility, and add more maintenance points with greasing pins. Alternatively, system pressure could be raised through the main valve to generate more force, but this would require more expensive valving and plumbing. Thus, there is a need for simplified hydraulic assemblies capable of selectively supplying power amplification to working cylinders.
Embodiments of the present invention are directed to a hydraulic circuit, which can be used to amplify the hydraulic power available to a hydraulic cylinder. The hydraulic circuit generally comprises a primary working cylinder, which can be selectively fed by a secondary power amplification cylinder. The circuit can include valves used to selectively apply power from the power amplification cylinder to the working cylinder. In certain embodiments, the power amplification can be used to provide an enhanced break-out force for a bucket cylinder, such as may be necessary for breaking out concrete, removing stumps, and/or high-force digging. Importantly, the power amplification operations according to embodiments of the present invention provide for an increase of force applied to the rode side of the working cylinder piston.
In one embodiment of the present invention, there is provided a hydraulic power amplification system comprising: a working cylinder comprising a first barrel, a first piston base slidably disposed within the first barrel and defining a first bore side chamber and a first rod side chamber, and a first piston rod extending from the first piston base through the first rod side chamber; and a pressure amplification cylinder comprising a second barrel, a second piston base slidably disposed within the second barrel and defining a second bore side chamber and a second rod side chamber, and a second piston rod extending from the second piston base through the second rod side chamber. The pressure amplification cylinder is configured to selectively provide hydraulic fluid to the working cylinder to amplify an operating pressure of the working cylinder. When the pressure amplification cylinder is providing the hydraulic fluid to the working cylinder, the second rod side chamber of the pressure amplification cylinder provides the hydraulic fluid to the first rod side chamber of the working cylinder.
In another embodiment of the present invention, there is provided a method for providing power amplification to a hydraulic cylinder assembly comprising a working cylinder having a working piston disposed therein and a pressure amplification cylinder having an amplification piston disposed therein. The method comprises: (a) introducing hydraulic fluid to a first rod side chamber of the working cylinder, the first rod side chamber being in fluid communication with a second rod side chamber of the pressure amplification cylinder; and (b) activating a power amplification operation by introducing a power amplification fluid to a bore side chamber of the pressure amplification cylinder so as to shift the amplification piston within the pressure amplification cylinder, thereby increasing the pressure of the hydraulic fluid within both the second rod side chamber of the pressure amplification cylinder and the first rod side chamber of the working cylinder.
In yet another embodiment of the present invention, there is provided a method for providing power amplification to a hydraulic cylinder assembly installed on a loader. The hydraulic cylinder assembly comprises a working cylinder and a pressure amplification cylinder. The method comprises: (a) introducing a hydraulic fluid to the working cylinder, thereby shifting a working piston disposed within the working cylinder and moving a loader attachment mechanically coupled to the working piston; and (b) activating a power amplification operation by shifting an amplification piston within the pressure amplification cylinder, the pressure amplification cylinder being in fluid communication with the working cylinder such that shifting the amplification piston increases the pressure of the hydraulic fluid within the working cylinder.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the present invention will be apparent from the following detailed description of the embodiments and the accompanying drawing figures.
Embodiments of the present invention are described herein with reference to the following drawing figures, wherein:
The drawing figures do not limit the present invention to the specific embodiments disclosed and described herein. The drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the invention.
The following detailed description of the present invention references various embodiments. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. The scope of the present invention is defined only by the appended claims, along with the full scope of equivalents to which such claims are entitled.
An exemplary hydraulic circuit for a power amplification system 10 is schematically illustrated in
Hydraulic working cylinder 20 generally comprises a barrel 22, a piston base 25 slidably disposed within the barrel 22, and a piston rod 24 extending from the piston base 25. The piston base 25 defines a bore side chamber 26 and a rod side chamber 28 within the barrel 22. The piston rod 24 extends through the rod side chamber 28 and is configured to extend from and retract within the barrel 22. The barrel 22 may include a barrel attachment bracket or other securement mechanism that is configured to facilitate securement of the working hydraulic cylinder 20 to a heavy-equipment machine (e.g., a loader), agricultural equipment, or the like. In addition, the piston rod 24 may include a rod attachment bracket or other securement mechanism secured to the distal end of the rod 24 (i.e., the end opposite the base 25) that is configured to be secured to a component or mechanism that is to be actuated via the extension and/or retraction of the piston rod 24
The barrel 22 includes a first port 27 located adjacent a first end of the barrel 20 and a second port 29 located adjacent an opposed second end of the barrel 22. The first port 27 is configured to allow hydraulic to flow into and out of the bore side chamber 26, and the second port 29 is configured to allow hydraulic to flow into and out of the rod side chamber 28. In operation, pressurizing the hydraulic working cylinder 20 by supplying hydraulic fluid to the bore side chamber 26 (via first port 27) will cause the piston rod 24 to extend outward from bore side chamber 26 of the barrel 22. In contrast, pressurizing the hydraulic cylinder 20 by supplying hydraulic fluid to the rod side chamber 28 (via the second port 29), while releasing pressure from the bore side chamber 26, will cause the piston rod 24 to retract within the barrel 22.
Pressure amplification cylinder 30 generally comprises a barrel 32, a piston base 35 slidably disposed within the barrel 32, and a piston rod 34 extending from the piston base 35. The piston base 35 defines a bore side chamber 36 and a rod side chamber 38 within the barrel 32. The piston rod 34 extends through the rod side chamber 38 and may be configured to extend from and retract within the barrel 32, although in some embodiments, piston rod 34 does not need to extend out of barrel 32. Pressure amplification cylinder 30 is configured to selectively provide hydraulic fluid to the working cylinder 20 to amplify an operating pressure of the working cylinder 20. In particular, the rod side chamber 38 of the pressure amplification cylinder 30 is in fluid communication with the rod side chamber 28 of the working cylinder 20. Thus, when power amplification of the working cylinder 20 is desired, the piston base 35 of the pressure amplification cylinder 30 is shifted in the direction of the rod side chamber 38 and provides hydraulic fluid to the rod side chamber 28 of the working cylinder 20, thereby increasing the operating pressure therein. In certain embodiments, pressure amplification cylinder 30 may comprise a spring 39 disposed within the rod side chamber 38 configured to bias the piston base 35 and to resiliently shift the piston base 35 toward the bore side chamber 36 after completion of an activation operation (or event).
Power amplification system 10 may further comprise one or more (or two or more) valves configured to control the flow of hydraulic fluids through the system 10. As noted above, main valve 40 is configured to selectively introduce and remove a working hydraulic fluid into and from the system 10. In particular, main valve 40 is configured to selectively introduce and/or remove hydraulic fluid to/from the bore side chamber 26 and the first rod side chamber 28 of the working cylinder 20. Main valve 40 may be a variety of valve types, but may generally comprise any of a variety of direction control valves. Although depicted as a single valve component, main valve 40 may comprise two or more separate valves.
In certain embodiments, system 10 may comprise a power amplification valve 50 configured to divert hydraulic fluid introduced by the main valve 40 from the working cylinder 20 to the pressure amplification cylinder 30. During a power amplification operation (or event), the power amplification valve 50 may be activated to introduce at least a portion of the hydraulic fluid introduced by the main valve 40 into the bore side chamber 36 of the pressure amplification cylinder 30. As shown, in certain embodiments, power amplification valve 50 may be in the form of a two-position valve, with the flow therethrough being controlled by a solenoid 52 and/or spring 54.
In certain embodiments, system 10 may comprise a check valve 60 positioned between the main valve 40 and the rod side chamber 28 of the working cylinder 20. The check valve 60 is configured to selectively inhibit hydraulic fluid within the rod side chamber 28 of the working cylinder 20 and/or within the rod side chamber 38 of pressure amplification cylinder 30 from flowing back toward the main valve 40. Thus, during a power amplification operation (or event), the check valve 60 can be utilized to maintain the increased pressure in the rod side chamber 28 of the working cylinder. As shown, in certain embodiments, check valve 60 may be in the form of a two-position valve, with the activation and deactivation of the check valve function being controlled by a solenoid 62 and/or spring 64.
As shown in
As shown in
As shown in
Exemplary methods for providing power amplification to a hydraulic cylinder assembly will now be described in more detail. Although reference is made to components of the systems depicted in
The piston base 25 of the working cylinder 20 may begin at least partially shifted toward the rod side chamber 28 such that the piston rod 24 extends at least partially out of the barrel 22. To effect movement of the piston rod 24 (and any attachments), hydraulic fluid from main valve 40 is introduced to the rod side chamber 28 of the working cylinder 20, thereby shifting the piston base 25 within barrel 22 in the direction of the bore side chamber 26.
When necessary or desired by the operator, a power amplification operation is activated by introducing a power amplification fluid to the bore side chamber 36 of the pressure amplification cylinder 30 so as to shift the amplification piston base 35 within the pressure amplification cylinder 30. For example, piston base 35 may be shifted in the direction of the rod side chamber 38 of the pressure amplification cylinder 30. This shift increases the pressure of the hydraulic fluid within both the rod side chamber 38 of the pressure amplification cylinder 30 and the rod side chamber 28 of the working cylinder 20. Generally, power amplification is achieved by increasing the effective area on the rod side of the piston base 25 of the working cylinder 20 by utilizing the area of the piston base 35 of the pressure amplification cylinder 35. Since the rod side chamber 38 of pressure amplification cylinder 30 is in fluid communication with the rod side chamber 28 of working cylinder 20, the piston base 35 of the pressure amplification chamber 30 can be utilized to increase the effective area of the rod side of piston base 25 of the working cylinder, thereby increasing the effective force applied to the rod side of piston base 25 (i.e., force=pressure x area).
In certain embodiments, as illustrated in
In certain embodiments, activation of the power amplification operation comprises selectively activating a solenoid 62 on check valve 60, thereby activating check valve 60 to inhibit the hydraulic fluid within the rod side chamber 28 of the working cylinder 20 and the rod side chamber 38 of the pressure amplification cylinder 30 from flowing toward the main valve 40. This operation of the check valve 60 can protect upstream hoses and components from over-pressurizing during the power amplification operation.
Alternatively, as illustrated in
After activation and completion of the power amplification operation, the solenoids 52, 62 on valves 50, 60 are deactivated, thereby shifting the valves 50, 60 back to normal operation. In doing so, at least a portion of the hydraulic fluid/pressure from the rod side chamber 28 of the working cylinder 20 and/or the rod side chamber 38 of the pressure amplification cylinder 30 may be released and allowed (or directed) to flow back toward main valve 40. Additionally, at least a portion of the hydraulic power amplification fluid from the bore side chamber 36 of the pressure amplification cylinder 30 is allowed to flow toward a hydraulic fluid reservoir 42. This allows or causes the piston base 35 of the pressure amplification cylinder 30 shifts toward the bore side chamber 36, decreasing the pressure of the hydraulic fluid therein.
Alternatively, after activation and completion of the power amplification operation, the hydraulic fluid flows out of the bore side chamber 36 through the check valve 152 back toward the main valve 40, thereby deactivating the pressure relief valve 150 and shifting the piston base 35 in the pressure amplification cylinder 30 in the direction of the bore side chamber 36.
In certain embodiments, the spring 39 disposed within the rod side chamber 38 of the pressure amplification cylinder 30 can supply at least a portion of the force necessary to shift the amplification piston base 35 toward the bore side chamber 36. Additionally, or alternatively, the flow of hydraulic fluid to the rod side chamber 38 of the pressure amplification cylinder 30 can supply at least a portion of the force necessary to shift the amplification piston base 35 toward the bore side chamber 36.
As noted above, upon completion of a power amplification operation, shifting of the piston base 35 in barrel 32 toward the bore side chamber 36 can cause a rapid drop in pressure of the hydraulic fluid within the rod side chamber 28 of the working cylinder 20 and cause a delay in the working cylinder 20 operation. However, in certain embodiments, the restriction element 70 at least partially inhibits flow of the hydraulic fluid from the rod side chamber 28 of the working cylinder 20 to the rod side chamber 38 of the pressure amplification cylinder 30, thereby reducing or eliminating the delay in operation of the working cylinder 20.
Embodiments of the present invention are particularly useful for hydraulic cylinder assemblies on heavy-equipment machines and/or agricultural equipment. In particular embodiments, the hydraulic circuits and systems may be used to provide supplemental breakout force to working cylinders on loader equipment, such as bucket loaders. Embodiments of the present invention can therefore function to apply more breakout force to the bucket of the bucket loader for a short interval of time. This power amplification can be particularly useful for breaking out concrete, removing stumps, and digging where more bucket breakout force is required.
Accordingly, certain embodiments of the present invention are directed to methods for providing power amplification to a hydraulic cylinder assembly installed on a loader. Exemplary loaders may include compact utility loaders, such as those described in U.S. Pat. No. 11,208,786, U.S. Patent Application Publication No. 2021/0031845, U.S. Patent Application Publication No. 2021/0032836, U.S. Patent Application Publication No. 2021/0032842, U.S. Patent Application Publication No. 2021/0032843, and U.S. Patent Application Publication No. 2021/0032847, each of which is incorporated by reference herein their entireties.
As shown in
As described above, a power amplification operation of the hydraulic cylinder assembly 4 can be activated by shifting an amplification piston within the pressure amplification cylinder. The pressure amplification cylinder is in fluid communication with the working cylinder 6 such that shifting the amplification piston increases the pressure of the hydraulic fluid within the working cylinder 6, thereby increasing the force applied to the piston base within the working cylinder 6. As described above, this the power amplification can be used to selectively provide an enhanced break-out force for the working cylinder 6, which supplies an interval of increased force to the loader attachment 8.
Although the invention has been described with reference to the one or more embodiments illustrated in the figures, it is understood that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims. Additionally, it should be understood that the features described in the embodiments herein may be included individually or in combination with one or more other features described herein in relation to one or more embodiments within the scope of the invention. Additional advantages of the various embodiments of the invention will be apparent to those skilled in the art upon review of the disclosure herein and the working examples below.
As used herein, the phrase “and/or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself or any combination of two or more of the listed items can be employed. For example, if an apparatus is described as containing or excluding components A, B, and/or C, the composition can contain or exclude A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.
Having thus described one or more embodiments of the invention, what is claimed as new and desired to be protected by Letters Patent includes the following:
