Patent Application
20210087779
The present disclosure generally pertains to ground engaging machines. More particularly this disclosure is directed toward a bi-metal cutting edge for ground engaging machines.
Earth moving equipment such as scrapers, dozers, dragline buckets, backhoes, shovel dippers, and the like are generally provided with a cutting component which is adapted to engage and displace earth. Because the main digging unit, for example the bucket of a dozer blade, is relatively expensive, it is desirable to provide a replaceable cutting component so that the cutting component main digging unit can be maintained relatively sharp without having to rework the entire bucket. The cutting component can be subject to intense abrasive wear from loads that cause high stress to the cutting component.
U.S. Pat. No. 8,241,761 to Garber et. al. describes a composite casting for a wear resistant surface. The composite comprises a base composed of a ductile material and a plurality of wear resistant inserts embedded in said base. The plurality of wear resistant inserts are composed of a carbide-containing wear resistant alloy which after casting is hot strained by forging or rolling. The inserts are arranged in the in base rows so that the inserts of each subsequent one of the rows overlap gaps between the inserts of a preceding one of the rows and (or) the inserts should be positioned with their side bases at an angle (relative to the movement of the abrasive material) of no less than 20° to prevent the wear of the ductile base of the composite castings.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventors or that are known in the art.
A cutting edge for a ground engaging machine is disclosed herein. The cutting edge includes a first layer and a second layer. The first layer formed of a first material and forming a front surface configured to engage a working material. The second layer formed of a second material harder than the first material. The second layer extending from the first layer away from the front surface.
The details of embodiments of the present disclosure, both as to their structure and operation, may be gleaned in part by study of the accompanying drawings, in which like reference numerals refer to like parts, and in which:
The detailed description set forth below, in connection with the accompanying drawings, is intended as a description of various embodiments and is not intended to represent the only embodiments in which the disclosure may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the embodiments. However, it will be apparent that those skilled in the art will be able to understand the disclosure without these specific details. In some instances, well-known structures and components are shown in simplified form for brevity of description. Furthermore, some of the features and surfaces have been left out or exaggerated for clarity and ease of explanation.
The power system 14 may include an engine such as, a diesel engine, a gasoline engine, a gaseous fuel-powered engine or any other type of combustion engine. It is contemplated that power system 14 may alternatively embody a non-combustion source of power such as a fuel cell, a power storage device, or any other type of power source. Power system 14 produces a mechanical or electrical power output that is then converted to mechanical, hydraulic, electrical, and/or other power for operating machine 10.
The propulsion system 16 includes a track-drive system incorporated with the machine undercarriage. In an alternative embodiment, the propulsion system 16 may include a wheel-drive system, or any other type of drive system to propel the machine 10. The propulsion system 16 may also include a transmission, a fluid pump (e.g., hydraulic system), and/or other devices to convert energy from the power system 14 to propel the machine 10 using the propulsion system 16. The propulsion system 16, including the undercarriage, is configured to receive power from the power system 14 and to convert that power to movement to propel the machine 10.
The machine 10 may further include one or more lift arms 18 pivotably coupled to the machine 10. One or more hydraulic cylinders 20 are operatively coupled between the frame 13 and the lift arms 18 to raise, lower, pivot, or otherwise manipulate the lift arms 18 and the blade rake 12. A hydraulic system (not shown) utilizes power from the power system 14 to generate pressurized fluid to operate the hydraulic system (including the hydraulic cylinders 20).
A coupler 22 may be coupled to the lift arms 18. The coupler 22 is configured to selectively attach to a blade rake 12, as shown in
Machine 10 further includes an operator station 24 supported by the frame 13. The operator station 24 is configured to hold an operator of the machine 10, and includes control devices configured to allow the operator to control operations of the machine 10 from the operator station 24. The operator station 24 may be open or may be enclosed within a cab, as desired.
The operator station 24 includes a seat 28, one or more operator interface device(s) 30 and one or more control panel(s) 32. The seat 28 is operatively coupled to the frame 13 and is configured to support the operator during operation of the machine 10. An operator interface device 30, such as a joystick, steering wheel, lever, knob, button, switch, and/or a variety of other interface devices receive input, such as motion, pressure, and etc., from the operator and communicate that input for controlling operation of the machine 10.
In operation, the operator sits in the seat 28 and manipulates one or more operator interface device(s) 30 (e.g., configured as joysticks having buttons, switches, and/or knobs), which causes the machine 10 to travel using the propulsion system 16 powered by the power system 14. In addition, manipulation of the operator interface device(s) 30 may cause the hydraulic system to operate the hydraulic cylinder(s) 20, which pivots the lift arm(s) 18, with respect to the frame 13 of the machine 10 to raise, lower, and/or pivot the blade rake 12.
The moldboard 120 can be configured to mount to machine 10. The moldboard 120 can be configured to engage, dig, or otherwise receive material, such as soil, rock, gravel, and/or other materials (not shown) to be moved by machine 10. The moldboard 120 is formed of a rigid material, such as steel, iron, or other material and has a front side 122. Thus, the front side 122 receives and moves material when lowered to a position to engage the material and when machine 10 is traveling generally in a forward direction. To efficiently move the material, the moldboard 120 can be generally formed having an arcuate profile shape, Such arc or radius shape allows the moldboard 120 to engage, push, and roll the material as the material moves up the moldboard 120 and tumbles forward while machine 10 moves in the forward direction. However, it is contemplated that the profile shape of the moldboard 120 may be other shapes.
The cutting edge 200 can include mounting holes 201. In an embodiment the mounting holes 201 can extend through the front surface 202 and through the back surface 204 (shown in
The cutting edge 200 can include first layer 210 and second layer 220. The first layer 210 can have a shape with a rectangular cross-section that extends along the length of the cutting edge 200. In other examples, the first layer 210 can be shaped to have a trapezoidal, arcuate, or other cross-section profiles that extend along the length of the cutting edge 200.
The first layer 210 can extend from the first end 206 to the second end 208 and can form a front surface 202. When the cutting edge 200 is mounted to the machine 10, the front surface 202 can be positioned to engage with working material. The front surface 202 can be substantially flat. In other examples the front surface 202 has an arcuate shape.
The first layer 210 can be of metal, such as rolled section steel, that can be quenched and tempered to a desired hardness. The first layer 210 can have a C scale Rockwell Hardness between 40 and 50. The first layer 210 can have a C scale Rockwell Hardness between 45 and 50.
The second layer 220 can extend from proximate the first end 206 to proximate the second end 208 and can form a back surface 204. In an embodiment the second layer 220 can extend from the first layer 210. The second layer 220 can extend from proximate the first end 206 to proximate the second end 208 along an interface with the first material of the first layer 210. The second layer 220 can be coextensive with the first layer 210 at the interface of the two layers 210, 220. When the cutting edge 200 is mounted to the machine 10, the back surface 204 can be positioned to be adjacent to and can contact the moldboard 120 of the machine 10. The back surface 204 can be substantially flat. In other examples the back surface 204 has an arcuate shape.
The second layer 220 can have a shape with a trapezoidal cross-section that extends along the length of the cutting edge 200. Of the two parallel sides of the trapezoid, the longer side can be positioned nearest to the first layer 210 and the shorter side can provide the back surface 204. The second layer 220 can have a second layer top side 222 and a second layer bottom side 224. The second layer top side 222 can be located proximate to the second end 208. The second layer top side 222 can extend diagonally from the adjacent to the second end 208 to adjacent the back surface 204. The second layer top side 222 and the interface between the second layer 220 and the first layer 210 can form a first angle θ1. In an embodiment the first angle θ1 is an acute angle. The second layer top side 222 and the back surface 204 can form a second angle θ2. In an embodiment the second angle θ2 is an obtuse angle.
The second layer bottom side 224 can be located proximate to the first end 206. The second layer bottom side 224 can extend diagonally from the adjacent to the first end 206 to adjacent the back surface 204. The second layer bottom side 224 and the interface between the second layer 220 and the first layer 210 can form a third angle θ3. In an embodiment the third angle θ3 is an acute angle. The second layer bottom side 224 and the back surface 204 can form a fourth angle θ4. In an embodiment the fourth angle θ4 is an obtuse angle.
In other examples, the second layer 220 can be shaped to have a rectangular, arcuate, or other cross-section profiles that extend along the length of the cutting edge 200.
The second layer 220 can comprise of highly hardenable, temper resistant steel that can be quenched to the desired hardness. The second layer 220 can have a C scale Rockwell Hardness above 60. The second layer 220 can have a C scale Rockwell Hardness between 55 and 65. The second layer 220 can have a C scale Rockwell Hardness around 60.
The cutting edge 200 can be manufactured by introducing a second material for the second layer 220 during the rolling process to provide alternative heat treatment response and higher hardenability in selected regions.
The first layer 310 can extend from the first end 306 to the second end 208 and can form a front surface 302. When the cutting edge 300 is mounted to the machine 10, the front surface 302 can be positioned to engage with working material. The front surface 302 can be substantially flat. In other examples the front surface 302 has an arcuate shape.
The first layer 310 can be metal, such as rolled section steel, which can be quenched and tempered to a desired hardness. The first layer 310 can have a C scale Rockwell Hardness between 40 and 50. The first layer 310 can have a C scale Rockwell Hardness between 45 and 50.
The second layer 320 can extend from the first end 306 to the second end 308. In an embodiment the second layer 320 can extend from the first layer 310 to the third layer 330.
The second layer 320 can have a shape with a rectangular cross-section that extends along the length of the cutting edge 300. In other examples, the second layer 320 can be shaped to have a trapezoidal, arcuate, or other cross-section profiles that extend along the length of the cutting edge 300.
The second layer 320 can comprise of highly hardenable, temper resistant steel that can be quenched to the desired hardness. The second layer 320 can have a C scale Rockwell Hardness above 60. The second layer 320 can have a C scale Rockwell Hardness between 55 and 65. The second layer 320 can have a C scale Rockwell Hardness around 60.
The third layer 330 can extend from proximate the first end 306 to proximate the second end 308 and can form a back surface 304. In an embodiment the third layer 330 can extend from the second layer 320. The third layer 330 can be coextensive with the second layer 320 at the interface of the two layers 320, 330. When the cutting edge 300 is mounted to the machine 10, the back surface 304 can be positioned to be adjacent to and can contact the moldboard 120 of the machine 10. The back surface 304 can be substantially flat. In other examples the back surface 304 has an arcuate shape.
The third layer 330 can have a shape with a trapezoidal cross-section that extends along the length of the cutting edge 300. Of the two parallel sides of the trapezoid, the longer side can be positioned nearest to the second layer 320 and the shorter side can provide the back surface 304. The third layer 330 can have a third layer top side 332 and a third layer bottom side 334. The third layer top side 332 can be located proximate to the second end 308. The third layer top side 332 can extend diagonally from the adjacent to the second end 308 to adjacent the back surface 304. The third layer top side 332 and the interface between the third layer 330 and the second layer 320 can form a fifth angle θ5. In an embodiment the fifth angle θ5 is an acute angle. The third layer top side 332 and the back surface 204 can form a sixth angle θ6. In an embodiment the sixth angle θ6 is an obtuse angle.
The third layer bottom side 334 can be located proximate to the first end 206. The third layer bottom side 334 can extend diagonally from the adjacent to the first end 206 to adjacent the back surface 304. The third layer bottom side 334 and the interface between the third layer 330 and the second layer 320 can form a seventh angle θ7. In an embodiment the seventh angle θ7 is an acute angle. The third layer bottom side 334 and the back surface 304 can form an eighth angle θ8. In an embodiment the eighth angle θ8 is an obtuse angle.
In other examples, the third layer 330 can be shaped to have a rectangular, arcuate, or other cross-section profiles that extend along the length of the cutting edge 200.
The third layer 330 can comprise of metal, such as rolled section steel, that can be quenched and tempered to the desired hardness. The third layer 330 can have a C scale Rockwell Hardness between 40 and 50. The third layer 330 can have a C scale Rockwell Hardness between 45 and 50.
The cutting edge 300 can be manufactured by introducing a second material for the second layer 320 during the rolling process to provide alternative heat treatment response and higher hardenability in selected regions.
The present disclosure generally applies to a cutting edge 200, 300 for a machine 10. It is understood that the cutting edge 200, 300 may be used with any stationary or mobile machine known in the art. Such machines may be used in construction, farming, mining, power generation, and/or other like applications. Accordingly, such machines may include, for example, excavators, track-type tractors, wheel loaders, on-road vehicles, off-road vehicles, generator sets, motor graders, or other like machines.
To increase the longevity or the usable life of the moldboard 120, the cutting edge 200, 300 can be formed of an alloy of metallic ground engaging materials. The cutting edge 200, 300 can include mounting holes 201 that can align with mounting holes in the moldboard 120 (not shown). The mounting holes of the moldboard 120 can be proximate the ground engaging or lower edge of the moldboard. The mounting holes 201 of the cutting edge 200, 300 and the mounting holes of the moldboard 120 can receive fasteners (not shown) to mount the cutting edge 200, 300 to the moldboard 120.
Conventional cutting edges are made of rolled section steel from a single material, which can be quenched and tempered to a hardness level that balances toughness and wear resistance. The lower hardness level is required to improve toughness, which results in reduction in wear resistance of the cutting edge.
The cutting edge 200, 300 utilizes a bi-metal composition to improve wear resistance and longevity. The cutting edge 200, 300 includes a second layer 220, 320, formed by a second material that can be highly hardenable and/or can comprise temper resistant steel in areas where stresses are less likely to cause brittle fracture. The second material is selected such that it responds more effectively to heat treatment which results in a higher hardness than the first material of the first layer 210, 310. As a result, this high hardness of the second layer 220, 320 improves overall wear resistance of the cutting edge 200, 300 and therefore extends its life. The cutting edge 200, 300 can include the second layer 320 positioned at the core or at the rear end of the cutting edge to increase wear resistance in the area. In other words the hardened layer 220, 320 is positioned in areas of the cutting edge 200, 300 likely to feel compression and can be positioned away from the direct contact of working material. In an embodiment, the bi-metal cutting edge 200, 300 is manufactured by using rolling process and includes a second material being added during the rolling process.
Although this disclosure has been shown and described with respect to detailed embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed disclosure. Accordingly, the preceding detailed description is merely exemplary in nature and is not intended to limit the disclosure or the application and uses of the disclosure. In particular, the described embodiments are not limited to use in conjunction with a particular type of machine 10. For example, the described embodiments may be applied to machines employed in mining, construction, farming, and power generation applications, or any variant thereof. Furthermore, there is no intention to be bound by any theory presented in any preceding section. It is also understood that the illustrations may include exaggerated dimensions and graphical representation to better illustrate the referenced items shown, and are not considered limiting unless expressly stated as such.
It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that have any or all of the stated benefits and advantages.
