Sensor for a Motor Grader

Abstract

A motor grader may include a moldboard assembly movably connected to a main frame of the motor grader to move with respect to a plurality of dimensions. The moldboard assembly may include a blade having a lower cutting edge, an upper free edge, and first blade side, and a second blade side. The moldboard assembly may be adapted to pivot the blade by moving the upper free edge with respect to the lower cutting edge. The moldboard assembly may be adapted to change the cross-slope of the blade by moving the first blade side with respect to the second blade side. To determine the pitch and/or cross-slope, a blade sensor may be mounted to the moldboard assembly. The location of the blade sensor on the moldboard assembly may protect the blade sensor and allow the blade sensor to directly measure the pitch and/or cross-slope of the blade.

We claim: 
     
         1 . A motor grader comprising:
 a main frame defining a longitudinal axis;   a moldboard assembly arranged generally traverse to the longitudinal axis, the moldboard assembly including a blade having an upper free edge, a lower cutting edge, a first blade side, and a second blade side, wherein the moldboard is movably connected to the main frame to:
 pivot the blade by moving the upper free edge with respect to the lower cutting edge; and 
 slope the blade by vertically moving the first blade side with respect to the second blade side; 
   a blade sensor disposed on and movable with the moldboard assembly, the blade sensor adapted to measure pitch of the blade and cross-slope of the blade.   
     
     
         2 . The motor grader of  claim 1  wherein the moldboard assembly is part of a drawbar-circle-moldboard (DCM) assembly including:
 a drawbar coupled to the main frame by a universal joint; 
 a circle assembly including a circle adapted to rotate with respect to the drawbar; and 
 the moldboard assembly, the moldboard assembly being pivotally connected to the circle assembly. 
 
     
     
         3 . The motor grader of  claim 2 , wherein the blade includes a curved front face and a rear support bracket, the blade sensor disposed on the rear support bracket. 
     
     
         4 . The motor grader of  claim 3 , wherein the moldboard assembly further comprises a hydraulic actuator is accommodated on the rear support bracket and the blade sensor is disposed on the hydraulic actuator proximate a hose coupling. 
     
     
         5 . The motor grader of  claim 3 , wherein the moldboard assembly further includes protective cover mountable to the rear support bracket for protectively accommodating the blade sensor. 
     
     
         6 . The motor grader of  claim 3 , wherein the DCM assembly further a pitch cylinder disposed between the moldboard assembly and the circle assembly, the pitch cylinder configured to extend and retract to pivot the moldboard assembly with respect to circle assembly. 
     
     
         7 . The motor grader of  claim 6 , wherein the moldboard assembly is pivotally connected to the circle assembly by a plurality of connecting arms. 
     
     
         8 . The motor grader of  claim 7 , wherein the plurality of connecting arms are joined to the rear support bracket by pivot joints proximate to the lower cutting edge. 
     
     
         9 . The motor grader of  claim 8 , wherein the blade sensor is disposed on the rear support bracket proximate to the pitch cylinder. 
     
     
         10 . The motor grader of  claim 2 , further comprising a first lift cylinder and a second lift cylinder, the first lifter cylinder and the second lift cylinder being independently actuated to vertically move the first blade side with respect to the second blade side. 
     
     
         11 . The motor grader of  claim 2 , wherein the moldboard assembly and the blade sensor are disposed vertically below the circle assembly. 
     
     
         12 . The motor grader of  claim 1 , wherein the blade sensor is a dynamic sensor. 
     
     
         13 . The motor grader of  claim 1 , wherein the blade sensor is an inertial measurement unit including one or more gyroscopes and one or more accelerometers. 
     
     
         14 . The motor grader of  claim 1 , further comprising a GPS receiver mounted to the moldboard assembly. 
     
     
         15 . A motor grader comprising:
 a main frame defining a longitudinal axis;   a moldboard assembly including a blade and movably connected to the main frame, the moldboard assembly adapted to move with respect to the main frame in a first dimension associated with a vertical axis perpendicular to the longitudinal axis and to move with respect to the frame in a second dimension associated with a lateral axis traverse to the longitudinal axis; and   a blade sensor mounted to the moldboard assembly, the blade sensor adapted to directly measure movement of the moldboard assembly in the first dimension and in the second dimension.   
     
     
         16 . The motor grader of  claim 15 , wherein the blade includes a lower cutting edge, an upper free edge, a first blade side and a second blade side; and wherein
 movement of the moldboard assembly in the first dimension corresponds to moving the upper free edge with respect to the lower cutting edge; and   movement of the moldboard assembly in the second dimension corresponds to   moving the first blade side with respect to the second blade side.   
     
     
         17 . A control system for a motor grader comprising:
 a drawbar-moldboard-circle (DCM) assembly including a drawbar movably connected to a frame of the motor grader, a circle assembly rotatably connected to the drawbar, and a moldboard assembly pivotally connected to the circle assembly;   a blade sensor disposed on a moldboard assembly of the motor grader, the blade sensor configured to measure pitch and cross-slope of the moldboard assembly;   and a controller in communication with the blade sensor to receive from the blade sensor a first signal indicative of pitch of the moldboard assembly and a second signal indicative of the cross-slope of the moldboard assembly, the controller further configured to process the first signal and the second signal to generate one or more control signals to control positioning of the moldboard assembly.   
     
     
         18 . The control system of  claim 17 , wherein the moldboard assembly includes a blade having a lower cutting edge, an upper free edge, a first blade side and a second blade side. 
     
     
         19 . The control system of  claim 18 , wherein the first signal indicative of pitch indicates relative position of the lower cutting edge and upper free edge, and the second signal indicative of cross-slope indicates relative position of the first blade side and the second blade side. 
     
     
         20 . The control system of  claim 19 , wherein the controller communicates the one or more control signals to one or more actuators operatively connected to the DCM assembly to position the moldboard assembly.