Dual Control To Optimize Work Modes For Operator Preference

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to heavy equipment and more specifically to dual control to optimize work modes for operator preference, which allows engine rpm and a swash plate angle of a hydraulic pump to be adjusted.

2. Discussion of the Prior Art

In excavator operations, there are various working modes generally provided to facilitate different types of construction work. An excavator works on an Idle Mode, a Standard Mode (Economy Mode) and a Power Mode. However, the work modes do not necessarily take into consideration different types of attachments to implement special workloads, such as hammering, sheering, thumbing, raking, grappling, etc. to meet the work requirements (i.e., higher power, higher torque, more precise controlling), the engine speed will be set or manipulated to different ranges on the traditional excavating machines.

State of the art excavators have three types of hydraulic control algorithms to manage the machine fluid power and flow: Negative Flow Control, Positive Flow Control and Load-Sensing Flow Control. The variable displacement pump utilizes variable swash plate angles to vary hydraulic flow. Adjusting the engine speed (RPM) and the swash plate angle of the variable displacement pump are used to fine tune the work modes of the excavators. Fine tuning the engine speed and swash plate angle will result in the excavator running more efficiently.

Accordingly, there is a clearly felt need in the art for dual control to optimize work modes for operator preference, which allows an operator to adjust engine rpm and a swash plate angle of a variable displacement pump to fine tune the operation of the excavator with or without different attachments.

SUMMARY OF THE INVENTION

The present invention provides dual control to optimize work modes for operator preference, which allows engine rpm and a swash plate angle of a variable displacement pump to be adjusted for optimizing the operation of different attachments. The dual control to optimize work modes for operator preference (dual control system) preferably includes a programmable controller, a control panel and a display interface. The control panel preferably includes an engine speed adjustment device, a swash plate angle adjustment device and a work mode on-off button. The engine speed adjustment device could be a rotary dial or any other suitable device for changing engine rpm of a primary mover, such as a diesel engine of the excavator. The primary mover is used to create hydraulic fluid flow from a variable displacement pump. The work mode on-off button is switched to the “on” position to show the current work mode on the display interface.

The display interface preferably includes a display of work modes, a display of attachment modes, a machine efficiency graphical display, an engine rpm graphical display, a swash plate angle graphical display, an engine rpm dial display and a swash plate angle dial display. The excavator includes a selection device for choosing a particular work mode. A choice of the work mode selection device is displayed on the display of work modes, when the work mode button is in the “on” position. The work mode display selections include Idle Mode (Idl), Grading Mode (Grd), Lift Mode (Lft), Standard Mode (Std), Power Mode (Pwr) and Attachment Mode (Atc). The excavator includes an attachment selection device for choosing a particular attachment. A choice of the attachment mode selection device is displayed on the display of attachment modes. The attachment mode display selections include Hammer, Sheer, Thumb, Rake, Grapple and Bracket. However, other mode display selections could also be used.

In North America, most operators use the highest power ratings, not standard power. Most operators want to get the work done. However, Standard (or Economy) Mode is popular with European operators. Economy mode can be used for leveling, light loading and fine precision work. In Europe, when the operators do fine grading, they don't want all of the power from the engine going to the front end of the machine. They want to reduce it down to keep the RPM as low as they can and maintain “controllability.” The dual mode system enables all of the work modes to be modified by adjusting the engine speed and swash plate angle to meet power, control, precision and efficiency requirements. To keep the excavators working more efficiently, both swash plate angle and engine speed are finely tuned and optimized to let the engine and the variable displacement pump run with power settings preferred by the operator.

The machine efficiency graphical display includes a percentage display of the machine efficiency. The machine efficiency is calculated by combining hydraulic pump efficiency and engine efficiency. The hydraulic pump efficiency is a ratio of engine power, which is consumed by the variable displacement pump for operating the excavator. Operating regions of the variable displacement piston pump and the engine are set according to the selected pump and engine manufacturers and will be monitored by control software of the programmable controller. The engine efficiency is calculated by the most efficient operating setting for the engine, which is in a region where the lowest fuel consumption occurs. Typically, fuel efficiency is better at lower engine speeds but there is also a region where power and efficiency are well matched. The engine rpm graphical display utilizes a tachometer output from the prime mover. The swash plate angle display obtains angle information by considering the pressure of the variable displacement piston pump, the flow rate of the pump, and the available power of the engine at the current engine speed setting. The swash plate angle is calculated from a power setting provided by the engine. The swash plate angle is then set by a proportional electrical current corresponding to a calculated swash plate angle.

The engine rpm dial display is provided with an electrical resistance value from the engine rpm dial to show the position of the engine rpm dial. The swash plate angle dial is provided with an electrical resistance value from the swash plate dial to show the position of the swash plate dial.

Additionally, the dual control system may be automated by providing a tuning algorithm. The tuning algorithm saves commonly used engine rpm and swash plate angle settings for combinations of work mode and attachment settings in an algorithm database, which were manually set by an operator. The algorithm database offers the choice of overriding the manual settings through an on-off button on the control panel and choose the combination settings of engine rpm and swash plate angle for work mode and attachment combinations, stored in the algorithm database through an algorithm toggle button on the control panel.

The dual control system provides the capability of optimizing the machine conditions and applications. With the control methodology, both engine and variable displacement pump can be regulated on their desired conditions to handle the workload. In addition, both negative flow and positive flow control excavators can simply apply the dual control with current controller units and feedback instruments.

Accordingly, it is an object of the present invention to provide dual control system, which allows an operator to adjust engine rpm and a swash plate angle of a hydraulic pump to fine tune the operation of the excavator in different work modes.

These and additional objects, advantages, features and benefits of the present invention will become apparent from the following specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of a control panel of a dual control system in accordance with the present invention.

FIG. 2 is a front view of a display interface of a dual control system in accordance with the present invention.

FIG. 3 is a schematic diagram of a dual control system in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference now to the drawings, and particularly to FIG. 3, there is shown a schematic diagram of a dual control system 1. With reference to FIGS. 1-2, the dual control system 1 preferably includes a programmable controller 10, a control panel 12 and a display interface 14. The control panel 12 preferably includes an engine speed adjustment device 16, a swash plate angle adjustment device 18 and a work mode on-off button 20. The engine speed adjustment device 16 could be a rotary dial or any other suitable device for changing an engine rpm of a primary mover, such as a diesel engine 100 of the excavator. The primary mover is used to power hydraulic fluid flow in a variable displacement pump 102. The work mode on-off button 20 is switched to the “on” position to show the current work mode on the display interface 14.

The display interface 14 preferably includes a display of work modes 22, a display of attachment modes 24, a machine efficiency graphical display 26, an engine rpm graphical display 28, a swash plate angle display 30, an engine rpm dial display 32 and a swash plate angle dial display 34. The excavator (heavy equipment) includes a work mode selection device 104 for choosing a particular work mode. The choice of the work mode selection device is displayed on the display of work modes 22, when the work mode button is in the “on” position. The work mode display 22 includes the selections include Idle Mode (Idl), Grading Mode (Grd), Lift Mode (Lft), Standard Mode (Std), Power Mode (Pwr) and Attachment Mode (Atc). The excavator (heavy equipment) includes an attachment selection device 104 for choosing a particular attachment. A choice of the attachment mode selection device 104 is displayed on the display of attachment modes 24. A choice of the attachment selection device 104 is displayed on the display of attachment modes 24. The attachment modes display selections include Hammer, Sheer, Thumb, Rake, Grapple and Bracket. However, other mode display selections could also be used.

An engine rpm adjustment soft dial 33 is preferably located within the engine rpm dial display 32. The engine rpm adjustment soft dial 33 may be used to adjust engine rpm. A swash plate angle adjustment soft dial 35 is preferably located within the swash plate angle dial display 34. The swash plate angle adjustment soft dial 35 may be used to adjust the swash plate angle of the variable displacement pump 102.

In North America, most operators use the highest power ratings, not standard power. Most operators want to get the work done. However, Standard (or Economy) Mode is popular with European operators. Economy mode can be used for leveling, light loading and fine precision work. In Europe, when the operators do fine grading, they don't want all of the power from the engine going to the front end of the machine. They want to reduce it down to keep the RPM as low as possible, so they can maintain “controllability.”

All the work modes can be modified by adjusting the engine speed and swash plate angle to meet power, control, precision and efficiency requirements. To keep the excavators working more efficiently, both swash plate angle and engine speed are finely tuned and optimized to let the engine 100 and the variable displacement pump 102 run under the most efficient conditions, through adjustment of the engine speed adjustment device 16 and the swash plate angle adjustment device 18.

The machine efficiency graphical display 26 includes a percentage display of the machine efficiency. The machine efficiency is calculated by combining hydraulic pump efficiency and engine efficiency. The hydraulic pump efficiency is a ratio of engine power, which is consumed by the variable displacement pump 102 for operating the excavator. Operating regions of the variable displacement pump 102 and the engine 100 are set according to the selected pump and engine manufacturers, and will be monitored by control software 36 of the programmable controller 10. The engine efficiency is calculated by the most efficient operating setting for the engine 100, which is in a region where the lowest fuel consumption occurs. Typically, fuel efficiency is better at lower engine speeds but there is also a region where power and efficiency are well matched. The engine rpm graphical display 28 utilizes a tachometer output from the engine 100, which is input into the programmable controller 10. The swash plate angle display 30 obtains angle information by considering the pressure of the variable displacement pump 102, the flow rate of the pump, and the available power of the engine 100 at the current engine speed setting. The swash plate angle is calculated from a power setting provided by the engine 100. The swash plate angle is then translated into a proportional electrical current corresponding to a calculated swash plate angle.

The engine rpm dial display 30 is provided with an electrical resistance value of an engine rpm dial 16 to show the position of the engine rpm dial 16. A swash plate angle dial 18 is provided with an electrical resistance value of the swash plate dial 18 to show the position of the swash plate dial 18.

Additionally, the dual control system 1 may be automated by providing a tuning algorithm contained in the control software 36. The tuning algorithm saves commonly used engine rpm and swash plate angle settings for combinations of work mode and attachment settings in an algorithm database 38, which are manually set by an operator. The algorithm database 38 offers the choice of overriding the manual settings through an on-off button 40, preferably on the control panel 12 and choose the combination settings of engine rpm and swash plate angle for work mode and attachment combinations, stored in the algorithm database 38, through an algorithm toggle button 42 on the control panel 12.

The dual control system 1 provides the capability of optimizing the machine conditions and applications. With the control methodology, both engine 100 and variable displacement pump 102 can be regulated on their desired conditions to handle the workload. In addition, both negative flow and positive flow control excavators can simply apply the dual control system 1 with current controller units and feedback instruments.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.