Patent Application
20160376771
The present disclosure relates generally to a wear measurement system and, more particularly, to a multi-sensor ultrasonic wear measurement system.
Machines, for example motor graders, dozers, wheel loaders, track loaders, rippers, hydraulic excavators, and backhoes are commonly used for excavating, grading, and various material moving applications. These machines include an implement or ground engaging tool having a leading edge for cutting, digging, scraping, or otherwise configured to contact earth or other material. Often, the tool is abraded during use of the machine and engagement of its leading edge with earth or other material. Such abrasion causes wearing of the tool, resulting in changes in its character and often a decrease in its effectiveness. It is because of such wearing that ground engaging tools often have wear elements removably attached to the ground engaging tool and replaced on a periodic basis.
Generally, there is an acceptable limit of wear that may occur before the wear element should be replaced. Commonly, whether this acceptable limit has been reached is a determination made by a service technician who may be called out to the machine to take measurements of one or more parameters of the worn tool. The measurements taken are then compared to the acceptable limit for that particular tool, with selective replacement of the wear element being based on the comparison. This process of determining when to replace the wear element can be time and labor intensive and of questionable accuracy.
At times, a focus on wear of a tool may be primarily on a change in its length, for example the length of a wear element. In other words, wear beyond an acceptable limit may generally equate to a decrease in length beyond an acceptable amount as the leading edge recedes from wear. However, often the length of a ground engaging tool may decrease, but it may not decrease uniformly. The material engaged by the tool may not be of uniform hardness and abrasiveness. Also, the leading edge may not always engage the material uniformly or with uniform force. This may leave a leading edge that has a non-uniform wear pattern such as a non-uniform decrease in length across its width. It would be desirable and beneficial to be able both to ascertain wear patterns that affect a decrease in length of a tool, and to ascertain wear patterns other than a straightforward decrease in length of the tool due to recession of its leading edge.
A way to measure wear or damage of a cutting edge of a tool is described in U.S. Pat. No. 5,777,231 to Patel et al. that issued on Jul. 7, 1998 (“the '231 patent”). Specifically, the '231 patent discloses producing ultrasonic signal pulses in a piezoelectric coating contacting a tool insert having a cutting edge. The ultrasonic signal pulses in the '231 patent are directed through the tool insert substantially toward a surface region of the tool insert that is in close proximity to the cutting edge of the tool insert. The ultrasonic signal pulses in the '231 patent that are reflected back from the surface region of the tool insert, through the tool insert, and into the piezoelectric coating, are detected and compared to a reference signal pulse reflected from the surface region before the tool insert is initially contacted to a workpiece.
Although the wear sensor of the '231 patent may offer a way to measure wear of a cutting edge, it may be problematic. For example, excavating, grading, material moving, and ground engaging equipment may be subjected to extreme forces and may come in contact with heavy and highly abrasive material. The system disclosed in the '231 patent appears to be limited to cutting machines and processes operating on a fixed workpiece where forces and workpiece materials are readily predictable. Accordingly, employing a system such as that disclosed in the '231 patent in the harsh and less predictable environment to which the ground engaging tools of excavating, grading, and material moving equipment tend to be exposed may not be efficient. The complexity of the system of the '231 patent, with its piezoelectric layer deposited on the cutting tool or on a seat for the cutting tool, renders the application of such a system to a ground engaging tool infeasible. In addition, the system of the '231 patent may not be adaptable for giving a measure of uneven wear of a ground engaging tool.
The wear measurement system of the present disclosure addresses one or more of the needs set forth above and/or other problems of the prior art.
In one aspect, the present disclosure is directed to a system for measuring wear performance of a ground engaging tool of a machine including a first ultrasonic sensor within the ground engaging tool configured to send pulses in a direction substantially at a perpendicular to an unworn leading edge of the ground engaging tool. The system also includes a second ultrasonic sensor within the ground engaging tool and configured to send pulses in a direction at an angle offset with respect to the perpendicular to the unworn leading edge of the ground engaging tool. The system also includes a wireless communication element associated with the first and second ultrasonic sensors and configured to send signals from the ultrasonic sensors. The system also includes a controller configured to receive the signals from the communication element and determine wear performance of the ground engaging tool based on the received signals.
In another aspect, the present disclosure is directed to a ground engaging tool including a base, a wear element removably mounted to the base, and a cavity formed within the wear element. The ground engaging tool also includes a first ultrasonic sensor in the cavity and configured to send pulses in a direction substantially at a perpendicular to an unworn leading edge of the wear element. The ground engaging tool also includes a second ultrasonic sensor in the cavity and configured to send pulses in a direction at an angle offset with respect the perpendicular to the unworn leading edge of the wear element.
In another aspect, the present disclosure is directed to a machine including a ground engaging tool operatively associated with the machine, the ground engaging tool including a wear element and a cavity within the wear element. The machine also includes first and second ultrasonic sensors located within the cavity and configured to send ultrasonic pulses through the wear element, and configured to receive echoes of the pulses, the first ultrasonic sensor being oriented to send pulses in a first direction substantially perpendicular to a leading edge of the wear element in an unworn condition, and the second ultrasonic sensor being oriented to send pulses in a second direction at an angle offset from the first direction. The machine also includes a wireless communication element located in the cavity and configured to send signals based on data generated by the first and second ultrasonic sensors, and at least one battery configured to power the wireless communication element and the first and second ultrasonic sensors. The machine also includes a controller configured to receive the signals from the communication element, perform a triangulation calculation based the signals to generate wear performance data, compare the generated wear performance data with stored data representative of expected wear performance, and generate one of a record, a notification, and a warning in response to the comparison.
GET 18 may be configured for movement relative to frame 22, for example, for lifting, lowering, and tilting relative to frame 22 by suitable links and hydraulic rams such as link 24, hydraulic ram 26, and hydraulic ram 28. GET 18 may include a base 30 held in place by a mounting member 32. A wear element 34 may be mounted to a forward end 36 of base 30. For example, base 30 may be a ripper shank and wear element 34 may be a ripper tip, as illustrated in
Wear element 34, mounted to forward end 36 of base 30, is illustrated separate from base 30 in
Leading edge 50 of wear element 34 (which also may be referred to as a cutting edge, a digging edge, a ground engaging edge, and other art recognized terms) may be configured to engage a material on work surface 12 (
First and second sensors 62 and 64 may be any shape, for example generally cylindrical, and together with communication element 66 and battery 68, may be mounted together within wear element 34 of GET 18, and in a package 69 within cavity 60 of wear element 34. Once package 69 with sensors 62 and 64 and associated components have been mounted within cavity 60, cavity 60 may be closed off, for example permanently sealed or provided with a removable cover. Package 69 may be any general shape, such as generally cylindrical or ovoid in shape. While a single battery may be sufficient for powering communication element 66 and first and second sensors 62 and 64, it is contemplated that multiple batteries may be provided. Accordingly, the term “battery” for purposes of this disclosure includes both a single battery and plural batteries. In addition, it is contemplated that both sensors 62 and 64 could be provided either with a single communication element 66 and battery 68, or each sensor 62 or 64 could be provided with its own separate communication element 66 and battery 68. Ultrasonic sensors 62 and 64 each may have a transducer configured to generate ultrasonic signal pulses within wear element 34. For example, first ultrasonic sensor 62 may have a first transducer 63, and second ultrasonic sensor 64 may have a second transducer 65.
Signal pulses generated by ultrasonic sensors 62 and 64 via their respective transducers 63 and 65 produce echoes upon reaching a surface of wear element 34, such as leading edge 50. These echoes return to a sensor 62, 64 and may then be detected by the sensors 62, 64. A time interval between sending a signal pulse and receiving an echo may then be determined, and this determined time interval may allow a distance from sensor 62, 64 to the targeted surface portion of leading edge 50 to be calculated. It is contemplated that the sensor 62, 64 may be configured, for example via a suitable microprocessor, to make the calculations, or the calculations may be made by controller 70 after receiving data from sensors 62, 64 via communication element 66. The distance calculated is indicative of the length of wear element 34 from the sensor 62, 64 to leading edge 50, for example. Over time, as leading edge 50 wears and wear element 34 decreases in length, the time interval from sending a signal to receiving an echo by a sensor 62, 64 will decrease and yield a calculation representing a decreased distance to leading edge 50 and a decreased length of wear element 34. In this way, wear performance of GET 18 may be ascertained.
Referring still to
Alternatively, sensors 62 and 64 may be arranged so that first ultrasonic sensor 62 is configured to receive echoes of pulses sent by second ultrasonic sensor 64, with second ultrasonic sensor 64 configured to receive echoes of pulses sent by first ultrasonic sensor 62. Where leading edge 50 of wear element 34 is in an unworn condition, or where leading edge 50 is in an evenly worn condition (e.g., worn parallel to the unworn leading edge 50), sensor 62, which sends pulses in a direction and along a path x substantially perpendicular to leading edge 50, will receive echoes in the form of reflected ultrasonic waves substantially along the same path x, and will permit, via straightforward calculation, an accurate determination of the distance from transducer 63 to leading edge 50. In the case of an evenly worn leading edge 50, the amount of recession of leading edge 50 then can be determined readily. Sensors 62 and 64 (as well as any additional sensors such as sensor 78 and its transducer 79 illustrated in dotted lines) each may be configured to recognize which sensor sent a signal that it may receive. That is to say, sensor 62 may recognize that a signal it has received was sent by sensor 64 (or sensor 78) and vice versa (along path y, for example). Thus when a worn leading edge 51, e.g., worn non-parallel to leading edge 50, is encountered by a signal from one sensor, the echo may be received and recognized by a different sensor.
Controller 70 may include a single microprocessor or multiple microprocessors that are configured to perform calculations necessary to accurately determine a wear pattern of leading edge 50 of wear element 34. Numerous commercially available microprocessors can be configured to perform the functions of controller 70. It should be appreciated that controller 70 could readily be embodied in a general machine microprocessor capable of controlling numerous machine functions. Controller 70 may include a memory, a secondary storage device, a processor, and any other components for running an application and/or processing and/or recording signals from sensors 62 and 64. Various other circuits may be associated with controller 70 such as power supply circuitry, signal conditioning circuitry, solenoid driver circuitry, and other types of circuitry.
One or more maps relating signals received via communication element 66 from sensors 62, 64 with wear patterns and various predetermined thresholds of wear for leading edge 50 of wear element 34 may be stored in the memory of controller 70. Each of these maps may include a collection of data in the form of tables, graphs, and/or equations. Controller 70 may be configured to select specific maps from available relationship maps stored in the memory of controller 70 to automatically determine and/or generate notifications regarding wear.
The notification generated by controller 70 may be shown on a display 72 associated with controller 70 and located within on-board operator station 18. The notification may provide a visual and/or audible alert regarding a current dimension of wear element 34, a wear pattern of leading edge 50, a remaining useful life of wear element 34, and/or a need to replace wear element 34. In this manner, the operator may be able to schedule maintenance of machine 10 and wear element 34 in advance of when leading edge 50 is worn so unevenly as to warrant replacement or when wear element 34 is effectively worn out.
Controller 70 may be able to communicate with an off-board entity 74 via a communication device 76. Communication device 76 may be configured to communicate messages wirelessly between controller 70 and off-board entity 74. The wireless communications may include satellite, cellular, infrared, and any other type of wireless communication. Off-board entity 74 may include, for example, service personnel, and the communications may include messages and/or data regarding wear information, such as wear pattern information relative to GET 18, wear element 34, and leading edge 50. Messages may include instructions for the service personnel, for example instructions relative to machine maintenance and/or replacement of worn wear elements.
The disclosed multi-sensor ultrasonic wear measurement system 100 may be used with any machine having a ground engaging tool, and may enhance the collection of data regarding wear characteristics, such as wear patterns, of removable wear elements. The disclosed multi-sensor ultrasonic wear measurement system may be capable of determining a current length of a wear element, a non-uniform (e.g., non-parallel) wear pattern of the leading edge of a wear element, an amount of useful life remaining in the wear element and its leading edge, and/or a wear rate of the leading edge. The disclosed system also may be capable of displaying notifications regarding these parameters and/or communicating the notifications to an off-board entity. The notifications may be generated continuously or, alternatively, only after a comparison with one or more threshold values indicates the need to generate the notification, for example when the remaining useful life and/or current length is approaching or is less than a threshold life or length of the leading edge.
Since at least two sensors (62 and 64) are mounted in parallel, with at least one of the at least two sensors sending ultrasonic pulses in a direction substantially at a perpendicular to an unworn leading edge of a ground engaging tool (e.g., an associated wear element of a ground engaging tool) and the other sensor sending pulses in a direction at an angle offset with respect to the perpendicular to the unworn leading edge of the ground engaging tool, error readings for changes in length of leading edge 50 may be avoided. With use of the disclosed arrangement of multiple sensors and taking two readings, one at an angle relative to the other, a non-uniform wear pattern across leading edge 50 may be detected. The angle of offset for a transducer will be known and may vary considerably, for example ranging from a few degrees (e.g., 1-5 degrees) to thirty degrees or more.
The various parameters, including width and length of a GET, distance between an ultrasonic sensor and a leading edge of the GET, spacing between sensors, and the angle relative to a sensor that pulses emanate, may be known from manufacturing specifications. The initial difference in time from sending an ultrasonic pulse from an ultrasonic sensor until receiving an echo of the pulse can readily be determined for a new, unworn GET. This is true both for a transducer that sends signals in a direction at a perpendicular to a leading edge and for a transducer that sends signals in a direction at a known angle relative to the leading edge. Given all these known parameters, controller 70 may be configured to perform a triangulation calculation, based on data generated from signals from the first and second ultrasonic sensors, to determine a wear pattern of the leading edge of the ground engaging tool.
Controller 70 may be configured to then generate data indicative of a wear rate of the ground engaging tool. Controller 70 also may be configured to communicate data relevant to wear performance of the ground engaging tool to off-board station 74. Controller 70 may be configured to determine and generate data indicative of both the wear rate of the ground engaging tool and a wear pattern of the leading edge of the ground engaging tool by comparing data based on signals received from the communication element 66 with stored data representative of an unworn ground engaging tool. Controller 70 also may be configured to compare data generated from signals received from communication element 66 with threshold data for creating a notification and may be configured to create a notification signal, in the form of an audible and/or visual notification, for example, based on the comparison. The notification signal also may be a displayed image, for example on display 72, representing current wear performance of the ground engaging tool.
It will be understood that more than two ultrasonic sensors may be employed in GET 18 in some embodiments. For example,
It will be apparent to those skilled in the art that various modifications and variations can be made to the multi-sensor ultrasonic measurement system of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the multi-sensor ultrasonic measurement system disclosed herein. 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 equivalent.
