US20020166267A1

US20020166267A1 - Advanced motor grader controls

Info

Publication number: US20020166267A1
Application number: US10/138,292
Authority: US
Inventors: Edward McGugan
Original assignee: Volvo Motor Graders Ltd
Current assignee: Volvo Motor Graders Ltd
Priority date: 2001-05-04
Filing date: 2002-05-06
Publication date: 2002-11-14
Also published as: WO2002090668A1; CA2345951A1

Abstract

A motor grader control arrangement uses a joystick control arrangement to control the operating functions of the motor grader. Two joystick controllers are provided on opposite sides of an operator's chair and the most convenient movement of each joystick controller, for example, fore-aft, side to side, and right and left rotation, are assigned to the most common grader adjustments. Each controller also includes an offset control surface with a series of thumb actuated press buttons for adjusting a given hydraulic component in a positive or negative response. The forward face of each joystick controller can include finger actuated press buttons. The distribution of the control functions between joystick controllers maintains similar activity to void operator fatigue in one hand. This also provides better operator control.

Description

FIELD OF THE INVENTION

The present invention relates to motor grader controls, and in particular, an improved control arrangement which uses right and left hand joystick controllers.

BACKGROUND OF THE INVENTION

Operation of a motor grader requires considerable skill due to the number of hand operated controls and the general complexity of motion associated with the various implements of the vehicle. The difficulty in achieving a satisfactory level of control is further compounded as the actuation direction of the traditional control levers of the vehicle is not necessarily aligned with the desired motion to be imparted to the actual implement. For example, the control lever could be a fore aft direction of movement for extending or contracting a side shift cylinder in basically a side to side direction. The fore aft movement of the lever has no direct correspondence to the movement of the actuator.

A motor grader due to its particular application and complexity has a host of different controls and requires extensive experience to become efficient.

As a result of the complexity of the machine and the numerous controls, the operator learning curve is long and relatively shallow. In addition, the previous controls have forced the operator to move his hands between different types of controls and actually release one control to move a different control.

There have been numerous proposals to simplify the controls and operation of a motor grader. United States Statutory Invention Registration H1, 831 discloses two joystick controllers for controlling the function of a motor grader. These joystick assemblies control the blade, the vehicle drive and the steering system of the vehicle. Attempts have been made to make the direction and motion of the controls more compatible with the implements that they control. Although it is recognized that a better control for a motor grader is required, the structure disclosed in the Statutory Invention Registration is quite complex and has not been readily accepted.

The present invention provides an improved control arrangement which overcomes a number of the difficulties described above.

SUMMARY OF THE INVENTION

The motor control arrangement according to the present invention comprises an operator seating position with a right hand joystick controller and a left had joystick controller mounted on opposite sides of the seating position. Each joystick controller controls a plurality of operating functions of the motor grader and each joystick is movable in a fore and aft direction, a side to side direction, and a right and left horizontal rotation. This provides six control functions.

Each joystick controller further includes a series of thumb actuator buttons with the buttons being paired and each pair controlling a hydraulic component. Actuation of one button of the pair causing a first direction of movement of the hydraulic component and actuation of the other button of the pair causing an opposite direction of movement of the hydraulic component.

According to an aspect of the invention, the hydraulic components controlled by the joysticks include any of hydraulic cylinders, hydraulic motors, hydraulic valves and hydraulic actuators.

According to a further aspect of the invention, each joystick controller includes an enlarged inwardly extending control surface and the series of buttons are located on the control surface.

According to yet a further aspect of the invention, each pair of buttons on the control surface has a unique textured surface associated therewith.

According to yet a further aspect of the invention, the unique textured surface associated with each pair of buttons is an elongate region, which extends between the respective buttons.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are shown in the drawings, wherein: [0013]
FIG. 1 is a side elevational view of a motor grader with various components thereof; [0014]
FIG. 2 is a perspective view of the joystick control arrangement; [0015]
FIG. 3 is a rear view of one of the joystick controllers; [0016]
FIG. 4 is a front view of the controllers; and [0017]
FIG. 5 shows distinctive shapes applied to the button actuators.[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The [0019] motor grader 2 has a rearwardly extending draw bar 3 attached to the front of the frame 4 with a high lift arrangement 6 supporting the rear of the draw bar. The grader blade 7 is supported below the draw bar and is rotatable about a vertical axis to change the angle of the grader blade 7 beneath the grader. The grader blade 7 is also slidable longitudinally beneath the draw bar and is tiltable in the fore aft direction to change the cutting angle.
The rear portion of the draw bar is movable beneath the grader frame from side to side of the motor grader by means of the side shift cylinder [0020] 5. High lift cylinders 10 control the position of the grader blade and move it from the raised position of FIG. 1 downwardly to a ground engaging position.
An operator controls the grader from within the [0021] cab 15. There have been a host of arrangements for controlling the motor of the grader, the transmission of the grader, the articulation of the grader, the lean of the front wheels of the grader, the steering of the front wheels of the grader, and a series of controls associated with the grader blade 7. Recently, it has been proposed to control the main operating functions of the grader, namely the various controls associated with the grader blade, and the steering and propulsion functions of the grader using joystick controllers provided at an operating station within the cab 15. The control arrangement 20 shown in FIG. 2 provides a significant advance and provides an ergonomic as well as intuitive control arrangement for the motor grader. The arrangement includes a left hand joystick controller 30 and a right hand joystick controller 32.
The following functions are controlled by the left [0022] hand joystick controller 30 and the right hand joystick controller 32. These controllers are positioned either side of the operator seating position generally shown as 34. The blade lift or height of the blade is controlled by the hydraulic lift cylinders 10 provided either side of the motor grader. The left blade lift cylinder is controlled by the fore aft movement 36 of the left controller 30. The right blade lift cylinder is controlled by the fore aft movement 38 of the right hand controller 32. Forward movement of the joystick controller causes the respective cylinder to lower and rearward movement of the controller causes the respective cylinder to lift the blade. This is the conventional direction of movement associated with the traditional series of control levers that grader operators are familiar with. These functions are the most often used of all of the blade controls and are the most important with respect to response time and accuracy. The controller channels associated with these movements are fully proportional in that the actuation of the hydraulic valve from the movement of the handle is accurate and is also designed electronically for precise proportional response based on movement of the respective joystick controller.
Steering of the wheels of the grader is controlled by the side to [0023] side movement 40 of the left hand controller. Left movement causes the wheels to steer left and right movement causes the wheels to steer right. This steering control is also fully proportional to allow the operator to control the grader in an efficient and time responsive manner.
Wheel lean of the front wheels is typically used for offsetting blade side loads. Basically, an angled blade can transfer a significant side load to the grader and leaning of the front wheels can assist in providing an efficient offsetting load. Left hand movement of the right hand controller causes the wheels to lean to the left and right movement causes the wheels to lean right. The wheel lean control movement is indicated as [0024] 42. This function is also fully proportional. It should be noted that a return to the neutral position maintains the lean that has been imparted to the wheels. If the wheels are to be returned to a more vertical position, then the joystick needs to be moved in the opposite direction.
The blade of the motor grader is supported on a very large rotatable gear, rotatably supported beneath the draw bar of the grader. This is commonly referred to as the circle turn. The rotation of the circle turn is controlled by rotating the left hand controller about its vertical axis as indicated by the [0025] movement 44. Rotation of the joystick controller in a clockwise manner moves the circle clockwise. Twisting of the handle of the controller in a counterclockwise direction moves the circle in a counterclockwise manner. This function is a simple on/off electronic control as the circle rotates slowly and therefore, can be controlled accurately without proportional electronics.
Articulation of the motor grader frame is also a function that is somewhat unique to a motor grader. Basically, the frame [0026] 4 of the motor grader is pivoted about a vertical axis at position 19 (FIG. 1) and the front wheels of the motor grader can be offset to either side of the tandem drive. Articulation of the grader frame is controlled by twisting the handle of the right hand controller about its vertical axis indicated as 46. Twisting the handle clockwise offsets the frame to the right or clockwise, and twisting the handle counterclockwise offset the frame to the left. Once again, this is a simple on/off function and is typically an adjustment that is completed relatively slowly. The right hand joystick controller controls the ability to articulate the grader frame once it has been released.
A motor grader also has the ability to allow the blade to float. Blade float allows the lift cylinders to move freely up and down as the blade follows the contour of the ground or road. This operation is initiated by double clicking the [0027] respective triggers 48 and 50 on the front of the left and right hand, pressing the trigger twice within a preset time limit, typically in the order of one second. Double clicking, pressing the trigger twice within a short time period allows the respective lift cylinders to float. Moving the left handle, for example, in the fore aft direction such as to directly control the left lift cylinder will result in the termination of the float feature and return to normal control. Thus the triggers 48 and 50 allow activation of the respective float feature of the lift cylinders. Thus, each joystick controller controls the respective lift cylinder float feature.
Blade tilt is controlled by the two left [0028] most buttons 52 and 54 on the rear or operator side of the left hand joystick. The upper button 52 when depressed will cause the blade to tilt forward. The lower button 54 when depressed will cause the blade to tilt rearwardly.
Each pair of buttons on a joystick controller preferably has a unique shape which is recognizable by touch. In this way, the operator can confirm without visually confirming his hand position that the correct button actuator is being engaged. Several different top surfaces of the buttons are shown in FIG. 5. In this case, one of the buttons has a projecting top surface, one of the buttons has a recessed grid top surface, and one button has a concave top surface. Other distinctive shapes and top surfaces can be used. [0029]
A motor grader also has the capability of having a series of different attachments mounted to the front of the grader. Typical attachments include a bulldozer blade type attachment and a snowplow attachment. The raising and lowering of the equipment is controlled by the two [0030] center buttons 56 and 58 on the rear or operator's side of the left joytstick controller handle. The upper button 56 when depressed will lower the attachment. Depressing the lower button 58 will raise the attachment; double clicking the upper button within a specified time period will float the front attachment. Activating either button again will disengage the float and return to the raising and lowering controls to the buttons.
A ripper or scarifier can be attached to the grader and is a toothed attachment used for tearing of a surface. There are certain types of rippers, which are attached to the rear of the motor grader, and there are other rippers secured behind the front axle of the motor grader. The raising or lowering of this equipment is controlled by the two right [0031] most buttons 60 and 62 on the rear or operator's side of the left controller handle. Depressing the upper button 60 will lower the equipment and depressing the lower button 62 will raise the attachment.
Motor graders are also used for snow plowing. In some cases, a snow wing is attached to one side of the grader for this particular function. The snow wing includes a forward mast and a rearward mast for raising and lowering of the snow wing. The front of the left controller is equipped with two buttons. The upper right button when depressed raises the front wing mast. The lower left button when depressed will lower the front wing mast. [0032]
The two lower [0033] most buttons 66 and 68 on the rear or operator's side of the right hand controller operate on the snow wing lift. Depressing the right button 68 causes the wing to lower or displace outwardly to the right. Depressing the left button 66 causes the wing to raise or displace inwardly to the left.
The snow wing also includes a rear snow wing mast. The [0034] front surface 51 of the right controller 32 is equipped with two buttons 70 and 72. Depressing the lower right button 72 will lower the rear mast. Depressing the upper left 70 button will raise the mast.
As previously described, the [0035] grader blade 7 is also slidable below the circle gear. The two upper most buttons 74 and 76 on the front face of the right hand joystick controller operate the blade slide. Depressing the right button 76 causes the blade to slide to the right, depressing the left button 74 causes the blade to slide to the left.
The position of the rear of the drawbar [0036] 3 is controlled by the side shift cylinder 5. The two center buttons 78 and 80 on the front face of the right hand joystick controller 32 operate the circle side shift cylinder. Depressing the right button 80 causes the drawbar to be displaced to the right and depressing the left hand button 78 causes the circle to displace to the left.
As can be appreciated, the operator controls the speed of the grader and the transmission of the grader. The [0037] left hand controller 30 is equipped with a three position rocker switch 82 with a small lock button. The switch, when rocked forward will place the transmission in the forward range. Rocking the switch rearwardly or downwardly will place the transmission in reverse. When the switch is in the center or neutral position, the transmission is in neutral. The lock button on the rocker switch prevents the switch from moving from the center position until the lock button is depressed and the switch moved into the desired position.
Transmission gear control is provided on the [0038] right hand controller 32. The controller has a three position momentary rocker switch 84 with a small lock button. The switch when rocked rearwardly will down shift the transmission. Rocking the switch in the opposite direction causes an up shift of the transmission. The lock button on the rocker switch prevents the rocker switch from moving from the center position until the lock button is depressed and the switch is rocked into the desired position.
Additional functions can be added to the control arrangement as required. [0039]
Turning to FIGS. 3 and 4, it can be seen that the joystick controllers have a [0040] grip portion 100 with a paddle or control portion 102 thereabove. The various buttons are provided on the control portion 102 and this area has also been textured about button pairs to allow the operator to recognize where his thumb is located for actuating appropriate buttons. As shown in FIG. 4, the left hand controller includes three unique textured areas 51, 53 and 55. Similarly, right hand controller 32 has unique textured areas 57, 59 and 61. The control buttons can also be shaped, colour coded or paired to provide a visual indication. The most frequently used controls are associated with the three way action of the joystick controllers. This is particularly true with respect to the fore and aft direction of the joystick controller and the side to side direction of the control stick of the controllers.
The stick portion or grip portion of the controller is always maintained in the operator's grasp and his thumb is primarily used for selecting of the various button controls. Some control buttons are provided on the front surface of the control portion [0041] 102 (See FIG. 3) and these can be actuated using one or two of the fingers of the operator. As can be appreciated, there is extensive movement and dexterity capabilities with respect to the operator's thumb and this provides easy control.
In the present design, the control functions of the motor grader have been divided or distributed such that each hand of the operator basically shares the numerous operating movements required to control the grader. In this way, each hand is active and one hand is not extensively overloaded. Consideration has been given to assigning the control functions in a logical, intuitive manner without overloading any one hand. Maintaining each hand active reduces hand and arm strain and reduces operator fatigue. In addition, better control of the grader is provided due to the sharing of the workload. The convenient layout and thumb and finger actuation allows easy transfer between grader functions. Control of two functions simultaneously, is also practical as each hand functions independently. [0042]
Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims. [0043]

Claims

1. A motor grader control arrangement comprising an operator seating position with a right hand joystick controller and a left hand joystick controller mounted on opposite sides of said seating position, each joystick controller controlling a plurality of operating functions of the motor grader, each joystick controller being movable in a fore aft direction, a side to side direction and a right and left horizontal rotation and thereby control six functions, each joystick controller further including a series of thumb actuated buttons with said buttons being paired and each pair controls a hydraulic cylinder with one button of the pair causing a first direction of movement of the hydraulic component and the other button of the pair causing an opposite direction of movement of the hydraulic component.

2. A motor grader control arrangement as claimed in claim 1 wherein said hydraulic components include any hydraulic cylinders, hydraulic motors, hydraulic valves and hydraulic actuators.

3. A motor grader control arrangement as claimed in claim 1 wherein each joystick controller includes an enlarged inwardly extending control surface and said series of buttons are located on said control surface.

4. A motor grader control arrangement as claimed in claim 3 wherein each pair of buttons on said control surface have a unique textured surface associated therewith.

5. A motor grader control arrangement as claimed in claim 4 wherein said unique textured surface is associated with an elongate region of said control surface extending between the respective buttons of the pair.

6. A motor grader control arrangement as claimed in claim 3 wherein said inwardly extending control surface is of a curved exterior shape.

7. A motor grader control arrangement as claimed in claim 6 wherein said control surface forms a paddle shaped extension of said joystick controller.

8. A motor grader control arrangement as claimed in claim 7 wherein some of said pairs of buttons are positioned on said control surface in a generally side by side relationship and some of said pairs of buttons are positioned on said control surface in a generally top bottom relationship.

9. A motor grader control arrangement as claimed in claim 2 wherein at least one of said joystick controllers includes one of said pairs of buttons on a rear surface of said joystick controller.

10. A motor grader control management as claimed in claim 1, wherein one of said joystick controllers, controls steering of front wheels of the grader by a side to side pivotting movement, and side to side movement of the other joystick controller, controls wheel lean of the grader.

11. A motor grader control arrangement as claimed in claim 1, wherein the control functions of the grader are assigned to said joystick controllers in a manner to distribute the workload therebetween such operation of the grader each hand of the operator is active.

12. A motor grader control arrangement as claimed in claim 3, wherein said series of buttons are pairs of buttons, and said pairs of buttons on each joystick controller have a different shape distinguishable by touch.