Patent Publication Number: US-2016238502-A1

Title: Method and system for determining hardness information of components

Description:
TECHNICAL FIELD 
     The present disclosure relates to determination of hardness information for components of a machine and more specifically, to a method and a system for determining hardness information of the case-hardened components of the machine. 
     BACKGROUND 
     Machines are equipped with components including idlers, rollers, track shoes, track chains, and sprockets among others. The components are heat treated to alter and improve their mechanical properties such as, but not limited to, hardness, strength, ductility, and toughness. The components are further inspected to determine the effect of heat treatment on their mechanical properties. Case-hardening is one of the heat treatment processes that is used to increase the hardness of a desired area of the component, while allowing other areas of the component to remain unaffected. 
     The current methods perform destructive testing for inspecting hardness of the case-hardened components. The destructive testing includes cutting out a cross-section of the component that is further analyzed for inspecting the hardness. Further, such methods consume a lot of time to inspect the components for conformance to part print. Also, the components that undergo the destructive testing cannot be reused leading to an increase in manufacturing costs. The current methods also include performing anon-destructive testing for inspecting hardness of the components. Such methods of performing non-destructive testing include electromagnetic methods, ultrasonic methods, among others. However, the accuracy of such methods decreases with increasing case-hardening depths of the components. Therefore, there is a need for providing improved method for inspecting hardness of the case-hardened components, that is reliable, efficient and that saves time and cost. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a method for determining hardness information of a component is disclosed. The method comprises forming at least one hole of a predetermined depth at a predetermined location on a surface of the component, measuring the hardness information of the component at the predetermined depth through the hole using one of a probe and a drill, and filling the at least one hole with a filler material. 
     Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a side view of a machine having an undercarriage assembly, in accordance with the concepts of the present disclosure; 
         FIG. 2  illustrates a pictorial view of a component section of the undercarriage assembly being tested for hardness, in accordance with the concepts of the present disclosure; 
         FIG. 3  illustrates a sectional view of the component section taken along a sectional line  3 - 3 ′ of  FIG. 2  and a probe for determining hardness information of the component, in accordance with an embodiment of the present disclosure; 
         FIG. 4  illustrates a sectional view of the component section taken along sectional line  3 - 3 ′ of  FIG. 2  and a drill for determining hardness information of the component, in accordance with an alternate embodiment of the present disclosure; and 
         FIG. 5  illustrates a flowchart of a method for determining hardness information of the component section, in accordance with the concepts of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a machine  10  includes a cabin  12 , an upper assembly  14 , and an undercarriage assembly  16  (hereinafter referred to as the assembly  16 ). The machine  10  further includes various other components which are not labeled in  FIG. 1  for the purpose of simplicity. The assembly  16  includes a number of components such as, but not limited to, idlers  18 , shoes  20 , carriage rollers  22 , rollers  24 , track chains  26 , and sprockets  28 . It would be apparent to one skilled in the art that the examples of the machine  10  are an excavator, a dozer, a multi-terrain loader, a cold planer, a hydraulic mining shovel among others without departing from the meaning and the scope of the disclosure. 
     During manufacturing, various components, i.e. the components of the machine  10  are subjected to heat treatment processes to alter their mechanical properties. The heat treatment processes include through-hardening and case-hardening, among others. Further, the components are tested for determining the hardness information in order to satisfy quality parameters. 
     Referring to  FIGS. 2 and 3 , equipment for testing the effect of case-hardening on a component section  30  is provided, The component section  30  is the cross-section of the components such as, but not limited to, the idlers  18 , the shoes  20 , the carriage rollers  22 , the rollers  24 , the track chains  26 , and the sprockets  28  (as shown in  FIG. 1 ). In an embodiment, the equipment includes a. probe  40 . The probe  40  is coupled to an electromagnetic instrument (not shown) which is further coupled to a computer (not shown). According to an alternate embodiment, the equipment includes a drill  40 ′ (as shown in  FIG. 4 ). It will be apparent to one skilled in the art that the method for testing the effect of case-hardening may also be applicable for any other component, such as a flywheel, a cylinder block, an engine block among others without departing from the meaning and scope of the disclosure. 
     Referring to  FIGS. 2 and 3 , according to the embodiment, at least one hole  32  of a predetermined depth L 1  and a diameter D 1  is formed within the component section  30 . The predetermined depth L 1  of the hole  32  extends from a surface  34  of the component section  30  to an end  36  of the hole  32 . The hole  32  is formed at a predetermined location on the surface  34  of the component section  30 . The predetermined location corresponds to a non-critical location on the surface  34  of the component section  30  so that forming the hole  32  at the predetermined location does not cause any failure in the component section  30 . It will be apparent to one skilled in the art that the predetermined depth L 1  of the hole  32 , the predetermined location of the hole  32 , the diameter D 1  of the hole  32  may vary without departing from the meaning and scope of the disclosure. 
     The probe  40  is inserted through the hole  32  at a number of depth points  38 . The probe  40  includes a body portion  42  and a shaft portion  44 . A diameter of the shaft portion  44  of the probe  40  is D 2 . The diameter D 2  of the shaft portion  44  of the probe  40  is less than the diameter D 1  of the hole  32  so that the shaft portion  44  easily slides within the hole  32 . It will be apparent to one skilled in the art that the probe  40  may be any of electromagnetic (such as eddy current and Barkhausen noise), ultrasonic, optical, and other types of sensors without departing from the meaning and scope of the disclosure. In an embodiment of the disclosure, the probe  40  is a surface mount eddy current probe. The probe  40  uses the principle of electromagnetic induction to determine the hardness information of the component section  30  at the number of depth points  38 . 
     When the probe  40  is inserted within the hole  32 , an output is recorded. An alternating current is created in a coil (not shown) of the probe  40 . The alternating current in the coil (not shown) of the probe  40  creates an alternating magnetic field in the coil (not shown) of the probe  40  which induces eddy currents in the component section  30 . The eddy currents in the component section  30  create an opposing magnetic field to the alternating magnetic field created in the coil (not shown). The interaction between the two magnetic fields the alternating magnetic field in the coil (not shown) and the opposing magnetic field in the component section  30 ) produces the voltage output. The output is further correlated with the hardness information of the component section  30 . Each depth point  38  from among a number of depth points  38  has an output proportional to the hardness information of the component section  30  at that particular depth point  38 . 
     The computer (not shown) has an algorithm that compares the hardness information recorded at each of the depth points  38  with the print required hardness at each of the depth points  38  to inspect the quality of the component section  30 . If the recorded hardness information conforms to the print required hardness, the component section  30  is passed for further manufacturing operations. If the recorded hardness information does not conform to the print required hardness, the component section  30  is discarded. After determining the hardness, the hole  32  is filled with a filler material to till the hole  32  formed on the surface  34  of the component section  30 . It would be apparent to one skilled in the art that the filler material may include materials such as, but not limited to, rubber, epoxy, and composites without departing from the meaning and the scope of the disclosure. 
     Referring to  FIG. 4 , according to the alternate embodiment, the hardness information of the component section  30  is determined using a force-feedback from the drill  40 ′. The hole  32  is formed at the predetermined location on the surface  34  of the component section  30  by the drill  40 ′. During drilling, the pressure required to drill the hole  32  at the depth point  38  is recorded in the form of force-feedback from the drill  40 ′. The force-feedback includes force and torque measurements along three axes of three-dimensional space. The force feedback is adjusted to include the effect of tool wear. The hole  32  is drilled further down and the force-feedback is recorded at the number of depth points  38  within the hole  32 . The force-feedback at each of the depth points  38  is correlated to the hardness information of the component section  30  at each of the depth points  38 . The hardness information recorded at the number of depth points  38  is compared with the print required hardness at the depth points  38  to conform quality requirements of the component section  30 . After the hardness is determined, the hole  32  is filled with the filler material. 
     INDUSTRIAL APPLICABILITY 
     Referring to  FIG. 5 , a method  46  for determining the hardness information of the component section  30  is described in conjunction with  FIGS. 2-3 , according to the embodiment of the present disclosure. At step  48 , the hole  32  of the predetermined depth L 1  at the predetermined location is formed on the surface  34  of the component section  30 . At step  50 , the probe  40  is inserted through the hole  32  and outputs are recorded for the number of depth points  38  inside the hole  32 . At step  52 , the outputs recorded at each of the depth points  38  are correlated with the hardness information at each of the depth points  38 . At step  54 , the hardness information at each of the number of depth points  38  is compared with the print required hardness to inspect quality of the component section  30 . At step  56 , the hole  32  in the component section  30  is filled with the filler material after quality inspection. 
     Referring to  FIG. 5 , the method  46  for determining the hardness information of the component section  30  is described in conjunction with  FIG. 4 , according to the alternate embodiment of the present disclosure. At step  48 , the hole  32  is formed at the predetermined location on the surface  34  of the component section  30 . At step  58 , during drilling, pressure at the number of depth points  38  inside the hole  32  is recorded in the form of force-feedback by the drill  40 ′. At step  60 , the force-feedback recorded at each of the depth points  38  is compared with the hardness information at each of the depth points  38 . At step  54 , the hardness information at the depth points  38  is compared with the print required hardness to inspect quality of the component section  30 . At step  56 , the hole  32  in the component section  30  is filled with the filler material after quality inspection. It will be apparent to one skilled in the an that the step  48  and the step  58  take place simultaneously without departing from the meaning and scope of the disclosure. It will be apparent to one skilled in the art that the hole  32  may be machined at a particular depth for the hardness measurement and the hole  32  may he further machined upto another depth for the hardness measurement without departing from the meaning and the scope of the disclosure. 
     The present disclosure discloses the partially non-destructive method  46  for determining hardness information of the components of the machine  10 . The method  46  reduces inspection time in contrast to the conventional destructive methods. Also, the hole  32  in the component section  30  is filled with the filler material after inspection, and thereby allows the component section  30  to be reused if the component section  30  meets the quality requirements. The method  46  is applied at various steps during a lifecycle of the component section  30 , such as during manufacturing, and overhaul that helps to accurately determine the remaining life of the component section  30 . 
     While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.