Patent Application
20140308061
This patent disclosure relates generally to construction and mining machinery and, more particularly, to a method and system for detecting positive coupling between a quick coupler and a work tool accessory.
Some quick coupler devices may allow the operator of a construction or mining machine to attach a work tool accessory to the arm of the machine through controls in the operator station of the machine without having to exit the operator station and manually attach the work tool accessory. These quick couplers greatly minimize downtime as the quick coupler may be attached to and detached from a work tool without requiring that a worker remove or attach the work tools by hand. The quick coupler is interposed at the junction between the machine and the work tool accessory. The work tool accessory is attached to the quick coupler, and the quick coupler is attached to the machine. The operator of the machine commands the quick coupler to release a work tool from inside the operator station. The machine is then repositioned to a second work tool accessory, where the operator may then manipulate the quick coupler to pick up the second work tool accessory.
Some quick couplers may rely on two recesses in the quick coupler for receiving a pair of attachment pins of the work tool accessory. An engagement mechanism is associated with one of the recesses for securing one of the attachment pins within one recess. The second attachment pin may be indirectly held within the second recess by the action of the engagement mechanism associated with the first recess. Other quick couplers, as disclosed in U.S. Pat. No. 7,882,898 to Vering, et al., may use a cylinder capable of being received by hooks on a work tool accessory and then at least two wedges that can be extended into and retracted from a wedge pocket on the work tool accessory. The extension of the two wedges may secure the work tool accessory to the machine, while the retraction of the two wedges may release the work tool accessory from the machine.
Some quick couplers where positive coupling with the work tool accessory is monitored are known in the art, but these systems rely on measuring cylinder pressure or cylinder length in respect to a pin on the work tool accessory, which can be inaccurate. The known systems may be dependent on taking multiple measurements to detect proper engagement with the work tool accessory. The need for multiple measurements leads to a higher chance that positive engagement may not be detected or may be falsely detected. The known systems may also be dependent on the pin of the work tool accessory having a predetermined diameter, which will limit the versatility of the machine
One aspect of the present disclosure is directed to a quick coupler, where one or more wedge engagement mechanisms are used to secure the work tool accessories to a machine, and a sensor is incorporated into each wedge that can detect the strain exerted on the wedge by the work tool accessory. The sensor may be incorporated into the body of the wedge mechanism for protection damage. When the wedge mechanism engages the work tool attachment mechanism, such as a pin, the wedge mechanism tends to bend slightly when wedge mechanism is forced under the pin. This bending moment is detected by the sensor and thereby reports that the work tool accessory is properly coupled to the quick coupler.
The present disclosure further contemplates a quick coupler where two engagement mechanisms, in the form of wedges, engage two work tool attachment mechanisms on the work tool accessory. The two engagement mechanism may each have a sensor incorporated into the body of the wedge mechanism where the sensor may be able to detect the strain forced on to the wedge during engagement with the work tool attachment mechanism. The sensors may be able to detect a bending moment on the wedge mechanisms or an axial moment. The sensors may then read the strain on the wedge mechanism back to an engine control module or add-on computer to determine if the work tool accessory is positively coupled with the quick coupler.
The present disclosure further contemplates a quick coupler where a proximity sensor may be incorporated into the wedge engagement system used to secure the work tool accessories to a machine. The proximity sensor may detect the distance between the wedge engagement system and the work tool accessory in order to determine positive coupling between the quick coupler and the work tool accessory.
Another aspect of the present disclosure is directed to a method for detecting work tool engagement including the steps of actuating an engagement mechanism, measuring a strain within the engagement mechanism, and determining whether the strain indicates positive coupling with a work tool attachment mechanism.
Another aspect of the present disclosure is directed to a machine having a quick coupler capable of attaching a tool to the machine while detecting whether the quick coupler has positively engaged the tool.
In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, may be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.
Tool system 120 may include linkage acted on by hydraulic cylinders to move a work tool accessory 160. Specifically, tool system 120 may include a boom member 130 that is vertically pivotal and controlled by first hydraulic mechanisms 131, and a stick member 140 that is vertically pivotal and controlled by a second hydraulic cylinder 141. Tool system 120 may further include a quick coupler 200 that is connected to the stick member 140 and is vertically pivotal and controlled by a third hydraulic cylinder 151. Tool system 120 may further include a work tool accessory 160 that is vertically pivotal and coupled with the quick coupler.
Numerous different work tool accessories 160 may be attachable to a single machine 100 and controllable via operator station 111. Work tool accessory 160 may include any device used to perform a particular task such as, for example, a bucket, a fork arrangement, a blade, a grapple, or any other task-performing device known in the art. Although connected in the embodiment of
The quick coupler 200 may be attached to a stick member 140 of a machine 100 at coupler pin openings 210 and 220. The quick coupler 200 may also contain a secondary recess 250 that may couple with a second work tool attachment mechanism 260. In some embodiments a latch or other enclosing mechanism may secure the second work tool attachment mechanism 260 within the secondary recess 250 of the quick coupler 200.
The value of the bending moment may be transferred to a central processing unit or an engine control module through a communication system. The central processing unit or engine control unit may determine whether the bending moment is above or below a predetermined threshold value and then may actuate an alarm system.
The first sensor 233 may also detect proximity between the first engagement mechanism 230 and the work tool attachment mechanism 240. The distance between the first engagement mechanism 230 and the work tool attachment mechanism 240 may be determined by the first sensor 233 and may correspond to negative coupling or positive coupling between the quick coupler 200 and the work tool accessory 160. The first sensor 233 may emit an electromagnetic field or a beam of electromagnetic radiation that is affected or returned by the work tool attachment mechanism 240. The first sensor 233 may then detect the change in the electromagnetic field or a beam of electromagnetic radiation or the return signal in order to determine the proximity between the first engagement mechanism 230 and the work tool attachment mechanism 240. The value of the distance between the first engagement mechanism 230 and the work tool attachment mechanism 240 may be transferred to a central processing unit or an engine control module through a communication system. The central processing unit or engine control unit may determine whether the distance is above or below a predetermined threshold value and then may actuate an alarm system.
The exemplary sensor 700 may also contain a voltage source 730 capable of transmitting voltage to gages 711, 712, 721, and 722. The exemplary sensor 700 may be capable of reading measurements into an engine control module or add-on central processing unit through wiring means. Other sensors may use wireless communication mechanisms to read measurements into an engine control module or add-on central processing unit.
The exemplary sensor 800 may also contain a voltage source 830 capable of transmitting voltage to gages 811, 812, 821, and 822. The exemplary sensor 800 may be capable of measuring the bending moment 840 at a higher resolution than exemplary sensor 700 in
The present disclosure also contemplates sensors using a multitude of other configurations of gages. This may include quarter bridge, half bridge, and full bridge configurations of gages where the gages are oriented to measure tensile, compression, and/or bending strain on the engagement mechanism.
The exemplary sensor 1100 may also contain a voltage source 1130 capable of transmitting voltage to gages 1111, 1112, 1121, and 1122. The exemplary sensor 1100 may be capable of reading measurements into an engine control module or add-on central processing unit through wiring means. Other sensors may use wireless communication mechanisms to read measurements into an engine control module or add-on central processing unit.
While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
The present disclosure is applicable to machines in the construction and mining fields where various work-tool accessories may be applied to the machine 100. Commonly excavators, backhoes, or loaders use a variety or work tools such as augers, buckets, hammers, forks, grapples, shovels, or other work tool accessories necessary to complete a certain task. Quick couplers 200, 900 are commonly used in the construction industry to allow the machine to interface with the variety of work tool accessories. Quick couplers 260, 900 may greatly expand the utility of a single machine. For example, a single excavator may be used for excavating dirt, rock and other material, and during the excavation operations different work tool accessories may be required, such as a different size of bucket, a hammer, or a grapple. The quick coupler 200 can be used to quickly change from one work tool accessory 160 to another while ensuring that the work tool accessory 160 is positively coupled to the stick member 140, thus reducing downtime for the machine 100 and ensuring that the machine 100 is safe to operate after switching between work tool accessories 160.
With the present disclosure if there is a miss-couple where the work tool accessory 160 fails to positively engage, the engagement mechanism 230 will not be under a strain and a false-positive will not be measured by the sensor in the engagement mechanism 230. The present disclosure also contemplates communication between a first sensor 233 in the engagement mechanism 230 and an engine control module of the machine 100 or another add-on central processing unit in the machine 100. After communication with the engine control module or add-on central processing unit a determination of positive coupling may be made and a warning message or alarm would sound if positive coupling is not present.
Measuring strain in the engagement mechanism 230 may be more accurate because only one variable must be measured and any calculation made to determine positive coupling between the quick coupler 200 and the work tool accessory 160 is not reliant on the diameter or other aspects of the work tool attachment mechanism 240 in the work tool accessory 160.
It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
