Patent Publication Number: US-2016222605-A1

Title: Method of controlling a plow of a paving machine

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to a paving machine. More specifically, the present disclosure relates to controlling a plow coupled with the paving machine. 
     BACKGROUND 
     Paving machines typically include a tractor with a hopper for receiving paving material. The hopper is located at the front of the paving machine. A feeder conveyor for delivering the paving material to a spreader auger is located to the rear of the paving machine. The auger distributes the paving material laterally behind the tractor to the road surface in front of a screed assembly. The screed assembly is drawn behind the paving machine by a pair of pivotally mounted tow arms. The screed smoothens out and compresses the paving material. The paving machine may be driven on wheels or may include a track assembly. The paving machine may further include a plow. The plow is an apparatus that aids in removing material such as obstacles and dirt etc. from in front of the wheels or tracks of the paving machine. Generally, the plow is mounted on the back side of a front bumper of the paving machine. 
     The plow has two operating configurations: a working configuration and a storage configuration. Typically, the plow is raised and lowered manually by an operator to toggle between the two configurations. Sometimes, this may lead to unintentional damage to the plow if the operator forgets to put the plow in the storage configuration after paving operation is completed. Mat defects may be introduced in the road surface during paving in case the plow is not lowered in to the working condition during paving. Further, the operator manually adjusting the plow may not be clearly visible from an operator station and may lead to safety concerns. 
     U.S. Pat. No. 7,033,105 discloses a road paving equipment having a tire track remover. The road paving equipment is provided with a pair of blade assemblies, each including a semi-flexible blade with a lower edge and an upper edge. The blade assembly is attached to the surface of a road paving vehicle near and behind the rear wheels of the vehicle in such a manner that the lower edge of the blade is in contact with the road surface. The blade assembly also includes means for vertical adjustment of blade while in use. The blade assembly levels the tire tracks created by the wheels of the road paving equipment on the road surface by vertically adjusting the blade assembly. 
     Thus, there is a need for a method to control the plow of the paving machine without manual interventions. 
     SUMMARY OF THE DISCLOSURE 
     In one aspect of the present disclosure, a method to control a plow of a paving machine is provided. The method receives a transmission signal indicative of a transmission status of the paving machine through a first sensor. The method receives a screed mode signal indicative of a mode of operation of a screed of the paving machine through a second sensor. The method further includes receiving a parking brake signal indicative of a parking brake status of the paving machine through a third sensor. Thereafter, the method includes controlling a position of the plow through a controller based on the transmission signal, the screed signal and the parking brake signal. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a paving machine having a plow, in accordance with one embodiment of the present disclosure; 
         FIG. 2  is a perspective view of the plow of the paving machine of  FIG. 1 , in accordance with one embodiment of the present disclosure; 
         FIG. 3  is a block diagram of a control logic of actuating the plow on the basis of operational parameters of the paving machine, in accordance with one embodiment of the present disclosure; and 
         FIG. 4  is a flow chart illustrating a method of controlling the plow, in accordance with one embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or the like parts. Referring to  FIG. 1 , an exemplary paving machine (hereinafter referred to as “the machine”) is illustrated. The machine  10  includes a tractor  12  having a frame  14  with a set of ground engaging members  16  coupled with the frame  14 . Though the ground engaging members are illustrated as wheels in  FIG. 1 , in various alternative embodiments, the ground engaging members may be tracks. The ground engaging members may include a set of front wheels  15  and a set of rear wheels  16 . The ground engaging members are driven by an engine  18  via a transmission (not shown). The transmission may be a hydrostatic transmission or a mechanical transmission. The machine  10  may also include a parking brake (not shown). 
     A screed assembly  20  is coupled to the tractor  12  and attached at a rear end of the machine  10  to spread and compact paving material into a layer or mat of desired thickness, size and uniformity on a ground surface. In the illustrated embodiment, the ground surface is abase surface on which a paving operation is performed. However, the ground surface may alternatively be a finished or an unfinished ground on which the machine  10  manoeuvres or travels without performing a paving operation. The machine  10  also includes an operator station  22  having a seat and a console, which may include various controls for directing operations of the machine  10 . The screed assembly  20  may also include an operator console  24 . 
     The machine  10  further includes a hopper (not shown) configured to store a paving material, and a conveyor system (not shown) including one or more conveyors configured to move the paving material from the hopper to the rear end of the frame  14 . The machine  10  further includes an auger (not shown) coupled to the tractor  12  and located between the tractor  12  and the screed assembly  20 . Specifically, the auger is placed at the rear end of the frame  14  and adjacent to the screed assembly  20 . The auger is configured to receive the paving material supplied by the conveyors and spread the paving material evenly ahead of the screed assembly  20 . 
     The machine  10  further includes plows  26  to remove any material such as obstacles, dirt etc. from in front of the set of front wheels  15 . The plows  26  are attached to a front bumper  28  of the machine  10 . Specifically, the plows  26  are attached to a back side of the front bumper  28 . Although only one plow  26  is visible in the side view of the machine  10  shown in  FIG. 1 , a similar plow  26  is attached in front of the other front wheel  15  which is not visible. 
     Referring to  FIG. 2 , the plow  26  includes a plate  30  and a scraper  32  attached to the plate  30 . The plate  30  may be rigid, and preferably fabricated from a metal. Any other material which suits the need of the application may also be used to fabricate the plate  30 . The scraper  32  may be fabricated from a hard plastic material or any other such material which suits the need of the application. The plate  30  has a first surface  36  and a second surface  38 . The scraper  32  is attached to the plate  30  on the first surface  36  using a fastening plate  42  and any known mechanical fastening means  34 , such as, nut and bolts. Specifically, the plate  30  includes multiple apertures (not shown) located at same horizontal level to receive the mechanical fastening means  34  therethrough, and the scraper  32  includes longitudinal slots  40 . After adjusting a height of the scraper  32  with respect to the ground surface, so that it either engages the ground surface or remains at a predefined distance from the ground surface, the fastening plate  42  is placed transversely over the longitudinal slots  40  so that a number of apertures  44  in the fastening plate  42  corresponds to the multiple apertures in the plate  30 . The mechanical fastening means  34  then couples the scraper  32  with the plate  30  through the fastening plate  42 . Since, the scraper  32  may wear at bottom and lose contact from the ground surface, the height of the scraper  32  can be re-adjusted through the longitudinal slots  40  to regain contact with the ground surface. 
     As shown in  FIG. 2 , a bracket  46  is attached to the second surface  38  of the plate  30 . The bracket  46  may be attached to the plate  30  by any mechanical fastening means. Alternatively, the bracket  46  may be attached to the plate  30  by welding, soldering or any other similar process. Further, an arm  48  is attached to the bracket  46  to couple the plow  26  with a hydraulic actuator  62  (shown in  FIG. 3 ), such as, a double acting hydraulic cylinder. 
     A control system  50  for controlling the plow  26  is shown in  FIG. 3 . The control system  50  includes a controller  52 . The controller  52  may be a single controller, or alternatively may include more than one controller controlling different functions and/or features of the machine  10 . The controller  52  may be an Electronic Control Module (ECM) of the machine  10 . The controller  52  is in communication with various sensors associated with the machine  10 . The controller  52  receives signals from various sensors including at least a first sensor  54 , a second sensor  56  and a third sensor  58 . 
     The first sensor  54  provides a signal indicative of a status of the transmission of the machine  10 . The status of the transmission may indicate a selected gear in a gearbox of the transmission. The first sensor  54  may detect a selected forward or reverse gear in the gearbox. The first sensor  54  may be a magnetic pick-up device that detects the movement of a gear tooth in the gearbox. The first sensor  54  generates signals indicative of the status of the transmission. The controller  52  receives signals from the first sensor  54  and determines the status of the transmission of the machine  10 . 
     The second sensor  56  provides a signal indicative of a mode of operation of the screed assembly  20 . The screed assembly  20  slides over the paving material to provide a uniform thickness. This mode of operation of the screed assembly  20  may be called as a float mode. The second sensor  56  determines whether the screed assembly  20  is operating in a float mode. The second sensor  56  may detect a distance between the screed assembly  20  and the ground surface to indicate the mode of operation of the screed assembly  20 . The second sensor  56  may be any type of sensor that may detect distance between the screed assembly  20  and the ground surface. Accordingly, the controller  52  receives signals from the second sensor  56  and determines the mode of operation of the screed assembly  20 . In another embodiment, the second sensor  56  may provide the controller  52  with a signal indicative of a distance between the screed assembly  20  and the ground surface. The controller  52  may have pre-stored information or look up tables to determine the mode of operation of the screed assembly  20  based on the signal provided by the second sensor  56 . 
     The third sensor  58  provides a signal indicative of a status of the parking brake. The third sensor  58  may detect whether the parking brake is activated. The parking brake system may utilize a mechanical, hydraulic or electronic means to activate or deactivate the parking brake on the machine  10 . The third sensor  58  may detect parameters such as a mechanical displacement, a hydraulic fluid pressure or an electric current etc. to determine whether the parking brake is activated. Accordingly, the controller  52  receives signals from the third sensor  58  and determines the status of the parking brake. 
     The controller  52  may also receive additional signals indicating operational parameters of the machine  10 . The operational parameters may include a speed of the machine  10 , an operating mode of the machine  10  such as a paving mode or a travelling mode. In an embodiment, the operator station  22  includes a function switch therein. The function switch is turned ON to start a paving operation. The controller  52  checks whether the function switch is ON to detect the operating mode of the machine  10 . Based on the signals received, the controller  52  determines if the machine  10  is in the paving mode. If the machine  10  is in the paving mode, the controller  52  controls the position of the plow  26  on the basis of the signals received from the first sensor  54 , the second sensor  56  and the third sensor  58 . The controller  52  determines whether the transmission signal provided by the first sensor  54  indicates the selection of a gear. The controller  52  determines whether the signal provided by the second sensor  56  indicates the mode of operation of the screed assembly  20  as the float mode. The controller  52  further determines whether the signal provided by the third sensor  58  indicates the status of the parking brake as deactivated. If the signals provided by the first sensor  54 , the second sensor  56  and the third sensor  58  meet the required conditions, the controller  52  moves the plow  26  to the engaged position. In case, any of the conditions are not met, the controller  52  moves the plow  26  to the stowage position. 
     The controller  52  controls the position of the plow  26  through a control valve  60 . The control valve  60  may be a check valve. The control valve  60  controls a supply of hydraulic fluid to the hydraulic actuator  62 . The hydraulic actuator  62  may be a dual acting hydraulic cylinder. A dual acting hydraulic cylinder includes a piston rod and ahead movable inside a cylindrical body. The cylindrical body may have a first end and a second end. The cylindrical body has openings for supplying hydraulic fluid on the first and the second end. The piston head is moved in the cylindrical body between the first end and the second end based on the supply of hydraulic fluid from either end. The two positions of the piston head on the two ends of the cylindrical body may correspond to an engaged position and a stowage position of the plow  26 . Depending upon the signals received from the first sensor  54 , the second sensor  56  and the third sensor  58 , the controller  52  determines the position of the plow  26 . Thereafter, the controller  52  controls the control valve  60  to supply hydraulic fluid to the hydraulic actuator  62 . The hydraulic actuator  62  actuates the arm  48  of the plow  26  to set the plow  26  in either of the engaged position or the stowage position. 
     Although the control of the plow  26  is explained by example of the dual acting hydraulic cylinder as the hydraulic actuator  62 , it should be understood that any other similar means to actuate the arm  48  of the plow  26  may be used without departing from the scope of the present disclosure. 
     INDUSTRIAL APPLICABILITY 
     Paving machines are used to lay a paving material on a ground surface. It is important to maintain a constant elevation of the ground surface being paved. This ensures quality of the finished surface. The plows  26  are provided in front of the ground engaging members  16  to clear any material in front of the ground engaging members  16  that may adversely impact the paving operation. However, currently the plow  26  has to be manually actuated between the engaged position and the stowage position. The present disclosure provides a method  64  of controlling the plow  26  based on the operating conditions of the machine  10 . The method  64  ensures that the plow  26  always remains in correct position for any operating condition of the machine  10  and avoid any physical damage to the bracket  46  of the plow  26 . Also, it helps in increasing the productivity of the paving operation by saving time incurred in manually actuating the plow  26 . Further, safety of the operator is also ensured which may otherwise be at risk while manually actuating the plow  26 . 
     The method  64  is explained with the help of a flowchart as shown in  FIG. 4 . The method  64  at step  66  receives the signal indicating the status of the transmission from the first sensor  54 . The controller  52  determines whether the gear is engaged in the forward or the reverse direction. The method  64  at step  68  receives the signal indicating the mode of operation of the screed assembly  20  from the second sensor  56 . The controller  52  determines whether the screed assembly  20  is operating in the float mode. The method  64  at step  70  receives the status of the parking brake by the third sensor  58 . The controller  52  determines whether the parking brake is deactivated. 
     The method  64  at step  72  controls the position of the plow  26  by the controller  52  based upon the signals provided by the first sensor  54 , the second sensor  56  and the third sensor  58 . The controller  52  determines the position of the plow  26  as the engaged position if the first sensor  54  indicates the status of the transmission as the gear selected in a forward direction, the second sensor  56  indicates the mode of operation of the screed assembly  20  as the float mode and the third sensor  58  indicates the status of the parking brake as deactivated. The controller  52  determines the position of the plow  26  as the stowed position if any of the above mentioned conditions are not met. The controller  52  controls the control valve  60  to supply hydraulic fluid to the hydraulic actuator  62 . The hydraulic actuator  62  may be the dual acting hydraulic cylinder or any other similar means. The hydraulic actuator  62  actuates the arm  48  of the plow  26  to set the plow  26  in either of the engaged position or the stowage position. 
     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.