Patent Grant
7269943
This invention relates generally to a method and apparatus for controlling a work tool and, more particularly, to a method and apparatus for controlling vibratory motion of a work tool.
During operation of work machines, it is sometimes desirable to move a work tool in a vibratory manner to accomplish some purpose. For example, an operator of an earth working machine having a work tool such as a bucket may desire to cause the bucket to move in a vibratory manner to (i) shake material out of the bucket that does not readily fall out, (ii) cause the bucket to penetrate hard material such as clay or rock, (iii) compact a surface, or (iv) perform some other function.
In the past, the standard method for vibrating a work tool has been for an operator to rapidly move the work tool control, such as a joystick or lever, back and forth until the task was completed. This method involves rapid motion by the operator that, over time, can become tedious and tiring. This technique is also only limited to certain work functions, such as shaking material out of the tool. Other functions, such as vibratory compaction of a surface, may not be efficiently performed by manual operation.
With the advent of electro-hydraulics, it has become possible to automate control of work tools in many ways that required manual control in the past. For example, computer-based controllers can be programmed to operate electro-hydraulic valves and solenoids with great precision, thus alleviating many of the difficult, tedious, tiring, or time-consuming tasks that operators previously had to perform.
In U.S. Pat. No. 5,860,231, Lee et al. discloses a system that automates the vibratory motion of a work tool by operator selection of a vibratory mode. The automatic method allows for work tool vibratory applications for several purposes, such as excavating, ground breaking, ground hardening (compaction), and the like.
Prior art devices and methods for controlling the vibratory motion of a work tool may still be improved by providing more sophisticated or more effective vibratory control mechanisms. For example, devices and methods may be desirable that effectively coordinate vibratory and non-vibratory operations among multiple work tool actuators.
The present invention is directed at overcoming one or more disadvantages associated with prior devices and methods for controlling vibratory operation of a work tool.
In one aspect of the present invention, a method for controlling a work tool on a work machine is provided, the work machine having first and second actuators, each actuator being operable in a vibratory mode and a non-vibratory mode, and each actuator being coupled to the work tool for changing the position of the work tool. The method may include simultaneously (i) operating the first actuator in a vibratory mode, (ii) operating the second actuator in a vibratory mode, and (iii) receiving a command to change the position of the work tool. The method may further include operating the first actuator in a non-vibratory mode to change the position of the work tool while operating the second actuator in a vibratory mode to vibrate the work tool, in response to receiving the command.
In another aspect of the present invention, a work machine is provided. The work machine may include a work tool, first and second actuators, a vibration control device, a work tool control device, and a controller. The first actuator may be operably coupled to the work tool for changing the position of the work tool and may be operable in a vibratory mode and in a non-vibratory mode. The second actuator also may be operably coupled to the work tool for changing the position of the work tool and may be operable in a vibratory mode and in a non-vibratory mode. The vibration control device may be operable to generate a vibration operation signal, and the work tool control device may be operable to generate a command signal to change the position of the work tool. The controller may be electrically coupled with the vibration control device, the work tool control device, and the first and second actuators. Further, the controller may be operable to, in response to receiving the vibration operation signal and the command signal, output a signal to operate the first actuator in a non-vibratory mode to change the position of the work tool while outputting a signal to operate the second actuator in a vibratory mode to cause vibration of the work tool.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate exemplary embodiments or features of the invention and, together with the description, serve to explain the principles of the invention. In the drawings,
Although the drawings depict exemplary embodiments or features of the present invention, the drawings are not necessarily to scale, and certain features may be exaggerated in order to better illustrate and explain the present invention. The exemplifications set out herein illustrate exemplary embodiments or features of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Reference will now be made in detail to embodiments or features of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same or corresponding reference numbers will be used throughout the drawings to refer to the same or corresponding parts.
With reference to
A work tool 104, mounted on the work machine 102, performs a work function of some type. The work tools 104a, 104b shown in
Without intending to be limiting in scope and application, the present invention is hereinbelow described with exemplary reference to a work machine 102 being a backhoe loader having a work tool 104a that is a bucket for digging or otherwise moving material.
The work machine 102 exemplified herein may include one or more actuators 106, for example hydraulic cylinders 106a, 106b, operably coupled to the work tool 104 for changing the position of the work tool 104a. The work machine 102 of
It is noted that the backhoe loader example is typically a hydraulically actuated machine. Other machines suited for use with the present invention may not necessarily include hydraulic actuation, and may instead rely on other types of actuation, such as electrical or mechanical actuation, for example.
With reference to
Referring to
It should be appreciated that the controller 302, in order to produce operation of the hydraulic cylinders 106a, 106b in a vibratory mode, may be configured to generate commands of desired amplitude and frequency and to deliver such commands to the electro-hydraulic valves 304 to cause desired operation of the work tool 104a in a vibratory, i.e., back and forth, manner. The desired amplitude and frequency may be determined as a function of one or more factors, such as the type of work tool 104a, the type of work machine 102, characteristics of the material being worked by the work tool, the type of work being performed, and the like.
An example of application of the present invention may be described with further reference to the block diagram of
The joystick 108 may be configured to deliver commands to the controller 302 to extend or retract the hydraulic cylinder 106a, for example when the joystick 108 is moved left or right. The joystick 108 may also be configured to deliver commands to the controller 302 to extend or retract the hydraulic cylinder 106b, for example when the joystick 108 is moved up or down. Thus, movement of the joystick 108 may cause—for example through the controller 302, the electro-hydraulic valves 304, and extension or retraction of the hydraulic cylinders 106a, 106b—a change in position of the work tool 104a.
Each button 202a, 202b may be configured to deliver a vibration operation signal to the controller 302 to indicate desired operation of each hydraulic cylinder 106a, 106b, respectively, in a vibratory mode. Moreover, a single button 202c may be configured to deliver a vibration operation signal to the controller 302 to indicate desired operation of both hydraulic cylinders 106a, 106b simultaneously. For example, in one scenario the work tool 104a may be filled with dirt and held stationary over a dirt pile. An operator may selectively activate one or more of the buttons 202 to operate one or both hydraulic cylinders 106a, 106b in a vibratory mode individually, sequentially, and/or simultaneously to facilitate removal of the dirt from the work tool 104a. It should be appreciated that termination of a vibration operation signal may be determined as an operator releases the respective button 202 which delivered the initial vibration operation signal. Alternatively, a vibration operation signal may be initiated and continued for a predetermined period of time (e.g., 30 seconds) upon activation of a respective button 202.
The controller 302 may further be configured to control and coordinate vibratory and non-vibratory operation of multiple hydraulic cylinders 106a, 106b, for example during movement of the work tool 104a. For example, the controller 302 may be configured to selectively prevent, at least temporarily, operation of one or both hydraulic cylinders 106a, 106b in a vibratory mode as a function of receiving one or more commands to change the position of the work tool 104a. In one exemplary arrangement, the controller is operable to cancel, nullify, or otherwise override a vibration operation signal relative a specific hydraulic cylinder 106a, 106b in response to receipt of a command to change the position of the work tool 104a via operation of the specific hydraulic cylinder 106a, 106b.
In an exemplary scenario, an operator may activate appropriate button(s) 102 to simultaneously operate the first and second hydraulic cylinders 106a, 106b in a vibratory mode. Upon receipt of a command from the joystick 108 to change the position of the work tool 104a via operation of a the first hydraulic cylinder 106a, the controller 302 may prevent operation of the first hydraulic cylinder 106a in a vibratory mode, for example even if a vibration operation signal relative the first hydraulic cylinder 106a is still being received by the controller 302. Thus, the controller 302 may cause operation of the first hydraulic cylinder 106a in a non-vibratory mode to change the position of the work tool 104a while operating the second hydraulic cylinder 106b in a vibratory mode to vibrate the work tool.
Alternatively or subsequently, upon receipt of a command from the joystick 108 to change the position of the work tool 104a via operation of the second hydraulic cylinder 106b, the controller 302 may prevent operation of the second hydraulic cylinder 106b in a vibratory mode, for example even if a vibration operation signal relative the second hydraulic cylinder 106b is still being received by the controller 302. Thus, the controller 302 may cause operation of the second hydraulic cylinder 106b in a non-vibratory mode to change the position of the work tool 104a while operating the first hydraulic cylinder 106a in a vibratory mode to vibrate the work tool.
Alternatively or subsequently, upon receipt of a command from the joystick 108 to change the position of the work tool 104a via operation of both the first and second hydraulic cylinders 106a, 106b, the controller 302 may prevent operation of the first and second hydraulic cylinders 106a, 106b in a vibratory mode, for example even if vibration operation signal(s) relative the first and second hydraulic cylinders 106a, 106b are still being received by the controller 302. Thus, the controller 302 may cause operation of the first and second hydraulic cylinders 106a, 106b in a non-vibratory mode to change the position of the work tool 104a.
As detailed hereinabove, the present disclosure provides an effective apparatus and method to desirably coordinate vibratory and non-vibratory work tool operations among multiple work tool actuators.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit or scope of the invention. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and figures and practice of the invention disclosed herein. It is intended that the specification and disclosed examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims and their equivalents. Accordingly, the invention is not limited except as by the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 5287699 | Takamura et al. | Feb 1994 | A |
| 5860231 | Lee et al. | Jan 1999 | A |
| 6725105 | Francis et al. | Apr 2004 | B2 |
| 6763661 | Tabor et al. | Jul 2004 | B2 |
| Number | Date | Country | |
|---|---|---|---|
| 20060248885 A1 | Nov 2006 | US |
