Abstract:
A ground engaging vehicle including a tool having a moving member and a control system controlling a speed of the moving member. The control system includes an adjustable proportional control and a triggering control. The adjustable proportional control creates a signal to thereby select a direction and a speed of the moving member. The triggering control setting the direction and/or the speed dependent upon the signal resulting in a set direction and a set speed, the triggering control subsequently setting the speed to zero.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a control system for hydraulics, and, more particularly, to a control system for auxiliary hydraulics of a ground engaging machine. 
         [0003]    2. Description of the Related Art 
         [0004]    Work machines, such as backhoes, skid loaders and other similar equipment typically have an operator station connected to a frame that is attached to movable elements that are hydraulically controlled. The moveable portions of the machine may include arms that are connected to tools, such as buckets, post hole diggers, rotating brushes, scraper blades, and/or any kind of assembly that is power driven or positioned by the hydraulic system of the work machine. 
         [0005]    Work machines commonly include an engine which drives a hydraulic pump that provides power to various components of the work machine. Attachments to the work machine typically include their own hydraulic motor for driving the attachment, yet are dependent upon the hydraulic system of the work machine to provide the pressurized fluid in the hydraulic system for driving the hydraulic motor of the attachment. Control systems of the work machine are often configured to provide operational control for the auxiliary hydraulic motors of the auxiliary systems. 
         [0006]    It is known to provide control levers in the form of joysticks with the joysticks including additional switches, triggers and other input devices for controlling electrical and/or hydraulic systems on the work machine. 
         [0007]    What is needed in the art is an improved hydraulic control system for controlling auxiliary systems attached to the work machine. 
       SUMMARY OF THE INVENTION 
       [0008]    The present invention provides a control system for auxiliary hydraulic systems attached to a ground engaging vehicle. 
         [0009]    The invention in one form is directed to a ground engaging vehicle including a tool having a moving member and a control system controlling a speed of the moving member. The control system includes an adjustable proportional control and a triggering control. The adjustable proportional control creates a signal to thereby select a direction and a speed of the moving member. The triggering control setting the direction and/or the speed dependent upon the signal resulting in a set direction and a set speed, the triggering control subsequently setting the speed to zero. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
           [0011]      FIG. 1  is a partially schematic side view of a work machine including an embodiment of an operator control system according to the present invention; 
           [0012]      FIG. 2  is a perspective view of an operator control system used in the work machine of  FIG. 1 ; 
           [0013]      FIG. 3  is a perspective view of one embodiment of an operator input assembly used in the operator control system of  FIG. 2 ; 
           [0014]      FIG. 4  is another embodiment of an operator input assembly of the present invention used in the operator control system of  FIG. 2 ; 
           [0015]      FIG. 5  is a schematic block diagram illustrating a method utilized by the control system of  FIGS. 1-4 ; 
           [0016]      FIG. 6  is a schematical block diagram of the control system that utilizes the method of  FIG. 5  and represents the control systems of  FIGS. 1-4 ; and 
           [0017]      FIG. 7  a schematical block diagram illustrating another method utilized by the control system of  FIGS. 1-4 . 
       
    
    
       [0018]    Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention and such exemplifications are not to be construed as limiting the scope of the invention in any manner. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    Referring now to the drawings, and more particularly to  FIG. 1 , there is shown a ground engaging vehicle  10  configured, for example, as a backhoe with an auxiliary attachment attached thereto. It is understood that ground engaging vehicle  10  can be any type of work machine, including, but not limited to, machines utilized in the construction, forestry and agricultural industries. Ground engaging vehicle  10  includes a moving member  12 , illustrated herein as a rotating brush  12  that is driven by a hydraulic system  14  of vehicle  10 . Rotating brush  12  includes an auxiliary hydraulic system  16  that is interconnected with hydraulic system  14 . Auxiliary hydraulic system  16  includes a motor that is driven by hydraulic system  14  from which pressurized fluid is routed. Ground engaging vehicle  10  additionally includes a control system  18  and an operator seating system  20 . Operator seating system  20  includes control devices that interact with control system  18  to provide electrical and hydraulic controls to ground engaging vehicle  10 . In addition to providing control to the elements of ground engaging vehicle  10 , control system  18  additionally controls auxiliary hydraulic system  16  by controlling the fluid flow and pressure to the hydraulic motor of auxiliary hydraulic system  16 . 
         [0020]    Now, additionally referring to  FIGS. 2-4  there is shown operating seating system  20  and includes a first control joystick  22  and a second control joystick  24 . The elements contained on one joystick  22  and/or  24  may be located on either joystick and the functions described hereafter will, for the sake of clarity and ease of understanding, be illustrated as existing on joystick  22 , although it is merely done for convenience and it is to be understood that the elements described may exist in combination between joysticks  22  and  24 . Joystick  22  includes a proportional controller  26  and a trigger  28 . Proportional control  26  can be in the form of a roller  26  that provides a proportional output based on its relative position. Trigger  28  can be thought of as an on/off switch that provides a triggering control and is energized when depressed and not energized when released. Proportional control  26  includes an extend range  30 , a retract range  32  and a neutral range  34 . Extend range  30  can also be understood to be a forward direction  30  and retract range  32  can be understood to be a reverse range  32 . This concept can be easily understood by considering the type of auxiliary attachment that may be connected to ground engaging vehicle  10 . For example, brush  12  rotates in either a forward or reverse direction hence reference to a forward range  30  and a reverse range  32  makes sense in this illustration. Alternatively, if moving member  12  had a linear motion portion it would be considered an extend range  30  and a retract range  32  that would be applicable thereto. For ease of illustration, the ranges for proportional control  26  will be referred to as forward range  30 , reverse range  32  and neutral range  34 . 
         [0021]    When proportional control  26  is released it is biased to return to a neutral position. A signal is produced by proportional control  26  that is analogous to the position of proportional control  26  throughout its range in both directions. A predetermined neutral range  34  is selected by control system  18  that is utilized to indicate that no input is being received from proportional control  26 . Proportional control  26  as it is positioned in this range may still be providing a signal but it is a signal that is interpreted as no input. The signal from proportional control  26  is altered when proportional control  26  is rotated in either direction. When proportional control  26  is rotated into forward range  30 , control system  18  interprets the position as a desired speed output as well as a forward direction. When proportional control  26  is moved into reverse range  32 , control system  18  interprets the positioning of proportional control  26  as a reverse command and the amount or relative position determines the speed that is to be provided to moving member  12 . 
         [0022]    Now, additionally referring to  FIG. 5  there is shown schematic illustration of method  100  that illustrates an embodiment of the present invention in the interoperation of proportional control  26  and trigger  28  in the control of moving member  12 . At step  102  a direction and speed to be applied to moving member  12  is selected by the positioning of proportional control  26 . Proportional control  26  is positioned either in forward range  30  or reverse range  32  and the relative positioning of proportional control  26  establishes the speed of motion to be applied to moving member  12 . When a desired speed and direction is achieved by moving member  12  trigger  28  is set at step  104  by depressing trigger  28 . This sets the direction and speed at step  106  that will then be repeated each time trigger  28  is depressed at step  110  to thereby use the direction and speed at step  108 . Alternatively, trigger  28  may act as a toggle in which one depressing of trigger  18  causes moving member  12  to operate at the selected direction and speed with the next depressing of trigger  28  toggling control system  18  to remove all power from moving member  12 . Additionally, the positioning of proportional control  26  may, apart from trigger  28 , cause the operation of moving member  12  in the direction and speed proportional to the positioning of proportional control  26 . 
         [0023]    Once trigger  28  is depressed at step  104  to set the direction selected by proportional control  26 , the speed of moving member  12  may be selected to be a predetermined speed different than that set by proportional control  26 , the predetermined speed may be a maximum speed of moving member  12 . The maximum speed being determined by the maximum hydraulic flow provided to auxiliary hydraulic system  16 . In this alternate operating method proportional control  26  effectively operates as a direction selecting device only with the speed already determined by control system  18 . 
         [0024]    The direction and speed selected is utilized at step  108  depending on trigger commands of trigger  28  interpreted at step  110 . At step  112  control system  18  is checking to see if proportional control  26  has been moved from a neutral position to a non-neutral position. Step  112  is only functional once proportional control  26  is returned to a neutral position after setting the direction and speed in step  102 . In step  112  control system  18  determines whether proportional control  26  is moved to a range other than neutral range  34 . If proportional control  26  remains in neutral range  34  then method  100  returns to step  110 . When proportional control  26  is moved to a position other than neutral range  34 , then at step  114  the speed and direction of moving member  12  is no longer controlled by trigger  28 . Trigger  28  is effectively deactivated so that it no longer controls the direction and/or speed of moving member  12 , until it is again set by the sequence of steps  102 ,  104  and  106 . Method  100  then will reinitiate once proportional control  26  is again returned to neutral range  34  and at that point proportional control  26  controls the direction and speed of moving member  12  by positioning proportional control  26  into forward range  30  or reverse range  32 . 
         [0025]    Now, additionally referring to  FIG. 6 , there is shown a schematical block diagram of control system  18  including control unit  36  and proportional valves  38  and  40 . When proportional control  26  is centered in neutral range  34 , channel  1  and channel  2  can be thought of as each providing a two and a half volt signal to control unit  36 . The selection of the actual voltage levels on channel  1  and channel  2  are arbitrary, but for ease of illustration the levels are understood to be half of the five volt level relative to the ground line. The mathematical total of the voltage on channel  1  and channel  2  are substantially equal to the difference between the five volt and ground line values, which are references for control unit  36 , and can be simply thought of as 5 volts. By requiring the total voltage on channels  1  and  2  to be approximately 5 volts electronic control unit  36  can evaluate the validity of the signals received from proportional control  26 . For example, if the total voltage on channel  1  and  2  is inside of a predetermined value, which for the sake of discussion will be plus or minus ½ volt the signal is considered valid and it is assumed that no signal line is broken from proportional control  26  to control unit  36 . However, if either channel  1  or channel  2  is interrupted or if an additional voltage is supplied thereon, then it is extremely unlikely that the voltage on channel  1  and  2  will be within the plus or minus one half volt window, thereby indicating that the signal from proportional control  26  is invalid and should be ignored by control unit  36 . The determination of an invalid signal can cause moving member  12  to stop. As proportional control  26  is moved from neutral position  34  the voltage on channel  1  moves opposite to the voltage on channel  2 , which may be accomplished with mechanically linked potentiometers that are wired to respectively increase and decrease the voltage on channels  1  and  2  relative to the position of proportional control  26 . 
         [0026]    As previously discussed, when the direction and/or speed of moving member  12  has been set at step  106 , each time trigger  28  is used to engage moving member  12  or disengage moving member  12  then proportional valves  38  and  40  are appropriately commanded based upon the signal received from trigger  28 . For example, proportional valve  38  operates in forward range  30  and is opened to the set position to replicate the flow to auxiliary hydraulic system  16  when trigger  28  is depressed. When trigger  28  is released proportional valve  38  will close. Valve  40  is used in a similar fashion if a reverse direction is selected from reverse range  32 . Proportional valves  38  and  40  may be operated to completely open in response to a command if maximum flow is required based on the foregoing discussion of the control of auxiliary hydraulic system  16 . 
         [0027]    Advantageously the present invention allows an operator to select the direction and the speed, depending upon the implementation, and once selected by a proportional control the auxiliary hydraulic unit can be alternately powered and disengaged by operation of a trigger switch. This allows for repeatability in the motion of a hydraulic unit and even though described as being an auxiliary control the same method can be utilized for hydraulic systems of ground engaging vehicle  10 , such as an extendable portion of a backhoe. 
         [0028]    Now, additionally referring to  FIG. 7  there is shown another schematic illustration of a method  200  that illustrates an embodiment of the present invention relative to the operation of proportional control  26 , also known as a bi-directional proportional control  26  or simply as a bi-directional control  26 , and trigger  28  in the control of moving member  12 . At step  202 , it is determined what the direction and speed that is being selected by bi-directional control  26  as it is positioned by an operator. Proportional control  26  is positioned either in forward range  30  or reverse range  32  and a relative positioning of proportional control  26  establishes the direction and speed of motion to be applied to moving member  12 . When the desired speed and direction is achieved by moving member  12 , trigger  28  is depressed at step  204  to set the speed and direction of moving member  12  so that the speed and direction or at least the direction can then be activated by subsequent action of trigger  28 . 
         [0029]    If trigger  28  is not depressed the method returns to step  202 . If trigger  28  has been depressed then at step  206  the output is set to thereby establish the direction and speed set by bi-directional/proportional control  26 . At step  208 , the output is active and method  200  checks at step  210  to see if there is an additional movement of bi-directional control  26 . If there is additional movement then method  200  returns to step  202 . If no further positioning of bi-directional control  26  takes place then method  200  proceeds to step  212  to check for the activation of trigger  28 . If trigger  28  has not been activated then method  200  returns to step  208 . If trigger  28  is activated at step  212  it toggles the output off at step  214  thereby stopping moving member  12 . If bi-directional control remains unmoved at step  216  then method  200  again checks for the actuation of trigger  28  at step  218 . If trigger  28  is triggered this causes method  200  to go to step  208  again activating moving member  12 . In this manner the actuation of trigger  28  toggles moving member  12  between no output and returning to the selected output direction and speed. The toggling aspect continues until bi-directional control  26  is actuated thereby returning method  200  to step  202 . 
         [0030]    While this invention has been described with respect to at least one embodiment, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.