Patent Application
20220042255
The present disclosure relates generally to mobile milling machines that may encounter chamber binding events, and more particularly, to a systems and methods for controlling the binding of a chamber of a mobile milling machine.
The present disclosure relates to milling machines that are used in road surface preparation or repairs. Milling machines are typically used to remove a layer or layers of ground surface or old or defective road surface in preparation for road formation or resurfacing. Many milling machines include a rotor having rotor bits for breaking up the ground surface, and include a rotor chamber to help direct the milled material toward a conveyor or back toward the surface. Such rotor chambers may include vertically movable chamber walls that surround the rotor and float along the ground surface during the milling operation. Thus, as the milling machine (and rotor) engages the ground, the movable walls can be urged upward by the ground surface. However, certain slopes of the ground surface or misalignment of the front or rear walls of the rotor chamber can cause a binding event that does not allow the front or rear movable walls to retract as the machine is lowered. Such a binding event may cause the machine to rest on the rotor chamber itself as the legs lower the machine rather than cutting deeper. This can cause one or more legs to raise off the ground and the target cut depth may not be achieved.
U.S. Pat. No. 8,246,270, issued to Berning, et al. (“the '270 patent”), describes a self-propelling road milling machine having a track assembly carrying the machine frame through lifting columns. A milling roller is supported on the machine frame for treatment of ground or roadways. The milling rotor is enclosed in a roll case having movable side plates and a movable rear stripping means. First and second sensor means are included for measuring milling depth by movement of the side plates and stripping means. The '270 patent, however, does not address binding of any of the walls of the roll case.
The systems and method of the present disclosure may solve one or more of the problems set forth above and/or other problems in the art. The scope of the current disclosure, however, is defined by the attached claims, and not by the ability to solve any specific problem.
According to one aspect of the present disclosure, a milling machine is provided comprising a frame including a plurality of height-adjustable legs; a rotor; a rotor chamber including a movable front wall, a movable rear wall, and a pair of movable side walls; and a controller. The controller is configured to enable a rotor chamber binding control during on a lowering of the rotor towards a ground surface; automatically raising at least one of the front wall or the rear wall during the lowering of the rotor; and disable the rotor chamber binding control.
According to another aspect of the present disclosure, a method of operating a milling machine is provided. The milling machine includes a frame having a plurality of height-adjustable legs; a rotor; and a rotor chamber including a movable front wall, a movable rear wall, and a pair of movable side walls. The method comprises enabling a rotor chamber binding control during a lowering of the rotor towards a ground surface; automatically raising at least one of the front wall or the rear wall during the lowering of the rotor; and automatically disabling the rotor chamber binding control.
According to another aspect of the present disclosure, a computer readable medium storing instructions for operating a milling machine is provided. The milling machine includes a frame including a plurality of height-adjustable legs; a rotor; and a rotor chamber including a movable front wall, a movable rear wall, and a pair of movable side walls. The computer readable medium, when executed by at least one controller, causes the one or more controllers to implement instructions for: automatically enabling a rotor chamber binding control during a lowering of the rotor; automatically raising at least one of the front wall or the rear wall during the lowering of the rotor; and automatically disabling the rotor chamber binding control.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the features, as claimed. The same reference numbers in different alternatives are used to describe the same components or functions. As used herein, the terms “comprises,” “comprising,” “having,” “including,” or other variations thereof, are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but may include other elements not expressly listed or inherent to such a process, method, article, or apparatus.
For the purpose of this disclosure, the term “ground surface” is broadly used to refer to all types of surfaces that form typical roadways (e.g., asphalt, cement, clay, sand, dirt, etc.) or can be milled in the removal or formation of roadways. In this disclosure, relative terms, such as, for example, “about,” “substantially,” “generally,” and “approximately” are used to indicate a possible variation of ±10% in a stated value or characteristic. The current disclosure is described with reference to a milling machine. As used herein, a milling machine includes any machine that includes a ground engaging rotor or cutter to displace ground surfaces. Examples of such milling machines include cold planers and ground reclaimers.
Referring to
Referring to
Actuators 46, 56, and 66 of rotor chamber 30 may be any type of actuator, for example hydraulic actuators. While only one actuator 46, 56, 66 is shown for each of the movable walls 40, 50, 60, it is understood that more than one actuator may be used for each wall. As generally shown by the dashed lines in
Referring to
As shown in
The disclosed machine binding detection and resolution systems and methods may be applicable to any machine having a rotor and rotor chamber 30, and may assist in resolving a binding event that can cause inefficient or detrimental operation of machine 10.
As shown in
Referring to
The determination of a rotor chamber binding event (step 420) may include determining a movement characteristic of at least one of the side walls 50. See step 422 of
Alternatively, determination of the a rotor chamber binding event (step 420) may be include using a machine height sensor, such as a sonic-type sensor, (not shown) that can communicate with controller 32 to compare the machine height with the movement of the leg actuators 24 (by position sensors 25). If the sensed height of the machine 10 is not commensurate with the position of the leg actuator 24, for example the machine 10 is sensed as being higher than the position derived from a position sensor of leg actuator 24, then a binding event is identified. Again, this corresponds to a binding of one or both of the front wall 40 or rear wall 60 with the ground and thereby not allowing the machine to lower even when the leg actuators 24 are retracted.
In response to the determination of a rotor chamber binding event (step 420) controller 32 may send signals to discontinue a floating state of one or more of the front and rear walls 40, 60, and raise one or both of the front wall 40 and the rear wall 60 (step 430). By actively moving the front or rear walls 40, 60, the respective actuators 46, 66 actively move one or more of the front or rear walls 40, 60 to lower the machine 10 and unbind the rotor chamber 30. The movement of the front and/or rear walls 40, 60 may continue until a raising of one or both of the side walls 50 is determined (by controller 32 and position sensors 58). At that point, the controller 32 disables the rotor chamber binding control (step 440).
The enabling or initiating of the rotor chamber binding control (step 410) takes place during a lower of the rotor 26 into a cut, and can be based on an operator command, such as an operator selecting an icon on the display 15 to enable rotor chamber binding control. Alternatively or in addition, the rotor chamber binding control may be initiated or enabled automatically when certain conditions of the machine 10 are met. In the case of such automatic initiation or enabling of the rotor chamber binding control, the operator may allow or disable the rotor chamber binding control as a user preference in the settings of the machine 10. As indicated in step 512 of
In response to the initiation or enabling of the rotor chamber binding control (step 410/512), controller 32 may send signals to automatically and periodically raise one or both of the front and rear walls 40, 60. In one aspect, only the rear wall 60 (e.g. moldboard scraper 64) will be controlled for periodic raising. For example, as the machine is being lowered into the cut, the rear wall actuators 66 will periodically raise the rear wall 60 for a first time period, and then place the raised wall in a float condition for a second time period, and repeat this raising and floating process until the machine rotor 26 has been lowered to a desired position. In one example, the first and second time periods may each be less than one second, such as the first time period may be approximately 500 ms, and the floating pause (second time period) may be approximately 400 ms. However, these particular time periods are exemplary only and may be other time periods. Further, the rise and float time periods may be varied during the lowering of the rotor 26. The time periods may be selected to allow the rear wall 60 to float back down after the first time period, and approximately maintain the rear wall 60 on the ground surface (i.e., prevent any significant gap between the rear wall 60 and the ground surface while the machine 10 is plunging into the cut).
When the controller 32 determines that the rotor 26 has been lowered to a desired position or depth (e.g. via position data 74), controller may disable the rotor chamber binding control (Step 540), thereby discontinuing the periodic raising of the rear wall 60 (and/or front wall 40). As used herein, a desired rotor position or depth corresponds to an actual depth of rotor 26, a height of machine 10, or any other measure that corresponds to a depth of rotor 26.
The above-described machine chamber control systems and methods may provide for a simple and automatic avoidance and/or resolution of a chamber binding event of a milling machine. Accordingly, the system and methods requires little or no user interaction to avoid or overcome a chamber binding event. Also, the system and method may provide for a more accurate cut by avoiding or automatically unbinding the system each time a binding event is sensed—even for less significant biding events that do not require substantial response, but nonetheless negatively affect the depth of cut. Further, by controlling the chamber binding event based on only certain sensors and/or movement of only certain actuators (e.g. side wall actuators 56 with position sensor 58, or leg actuators 24 via position sensor 25) less sensors are required on machine 10.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed machine without departing from the scope of the disclosure. Other embodiments of the machine will be apparent to those skilled in the art from consideration of the specification and practice of the system and methods described herein. For example, the above described process steps need not be performed in the order described, but rather certain steps can be performed in a different order and/or can be performed simultaneously with other steps. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents.
