Patent Application
20130079999
This disclosure relates generally to a system and method for controlling the engine and rotor speeds of cold planers for optimizing performance and fuel efficiency.
Cold planers, also known as pavement profilers, road milling machines or roadway planers, are machines designed for scarifying, removing, mixing or reclaiming material from the surface of bituminous or concrete roadways and similar surfaces. Cold planers typically have a plurality of tracks or wheels which adjustably support and horizontally transport the machine along the surface of the road to be planed. Cold planers also have a rotatable planing rotor or cutter that may be mechanically or hydraulically driven. Vertical adjustment of a cold planer with respect to the road surface may be provided by hydraulically adjustable rods that support the cold planer above its tracks or wheels.
While the rotor may be driven hydraulically, such hydraulically powered motor systems are typically less efficient at transmitting power to the rotor than mechanical drive arrangements which directly connect the rotor to the engine through a clutch. Mechanical drive arrangements are also particularly suited for mounting the rotor directly on the frame of the cold planer. Mounting of the rotor, or more specifically the rotor bearing housings, directly on the vehicle frame provides rigidity between the rotor and the machine suspension system thereby minimizing undesirable deflection of the rotor during the surface milling or planing operation. For these reasons, it may be desirable to mount the rotor and the engine driving the rotor directly on the cold planer frame and provide a direct mechanical drive between the engine and the rotor.
This disclosure is directed to cold planers that work on a variety of conditions that may require different rotor speeds or where different rotor speeds could be beneficial. In cold planers where the rotor is connected directly to the engine via a clutch and belt system, the speed of the rotor cannot be changed independently of the engine speed.
Two problems are associated with this type of cold planer. First, frequent changing of the rotor speed and therefore the planing operation at hand, may cause substantial wear and tear on the clutch. Second, while a direct mechanical connection between the engine and rotor is more efficient, cold planers still consume large quantities of fuel, which can substantially affect operating costs.
Therefore, a control system is needed for cold planers that work on a variety of conditions thereby requiring a variety of different rotor speeds. Such a control system may be designed to help protect clutch life and/or reduced fuel consumption.
A cold planer is disclosed which includes an engine coupled to a clutch. The clutch is detachably engaged with a rotor. The engine and clutch are linked to a controller. The controller is also linked to a control console. The control console includes a plurality of operator inputs. The plurality of operator inputs includes a rotor speed control switch and a propel enable switch. The rotor speed control switch has at least an off position, an on position and a plurality of different engine speed positions. The propel enable switch sends a signal to the controller to allow the cold planar to move.
The controller is programmed to adjust the engine speed to a first speed when (1) the engine is running, (2) the rotor speed control switch is switched to the on position and (3) the clutch is not engaged with the rotor. In an embodiment, the first speed can range from about 800 to about 1100 rpm.
The controller is also programmed to send a signal to the clutch to engage the rotor when the engine reaches the first speed. The controller is also programmed to adjust the engine speed from the first speed to a second speed that is greater than or equal to the first speed when the engine is running at the first speed and after the controller has sent a signal to the clutch causing the clutch to engage the rotor. In an embodiment, the second speed may range from about 1100 rpm to about 1300 rpm.
The rotor speed control switch may be a toggle switch or similar device with two active positions. The rotor speed control switch changes what the desired setting is and an LED display above or near the switch indicates the desired setting. The engine does no elevate to the desired speed until either the propel enable switch is pressed, the machine is manually lowered or automatically lowered with the grade/slope adjustment mechanism.
And, upon activation of the propel enable switch, the timer is activated and, if a predetermined time period has elapsed without movement of the cold planer, the controller is programmed to return the engine to the second speed.
A method for controlling the speed of an engine and a rotor of a cold planer is also disclosed. The method includes providing the cold planer with an engine coupled to a clutch. The clutch is detachably engaged with a rotor. The engine and clutch are linked to a controller. The controller is also linked to a control console and a timer. The control console includes a plurality of operator inputs that include a rotor speed control switch and a propel enable switch. The rotor speed control switch has at least an off position and an on position.
The method also includes adjusting the engine speed to a first speed when the engine is running and the rotor speed control switch is switched to an on position and the clutch is not engaged with the rotor.
The method also includes engaging the rotor with the clutch when the engine reaches the first speed. The method also includes adjusting the engine speed from the first speed to a second speed after the clutch has engaged the rotor.
The method also includes adjusting the engine speed from the second speed to a third speed that is higher than the second speed when the rotor speed control switch is switched to a third speed position. And, the method also includes activating the timer upon activation of the propel enable switch and, if a predetermined time period elapses without movement of the cold planer, returning the engine speed to the second speed.
Another cold planer is disclosed which comprises an engine coupled to a clutch. The clutch is attachably engaged with a rotor. The engine and clutch are linked to a controller. The controller is also linked to a control console. The control console includes a plurality of operator inputs including a rotor speed control switch and a propel enable switch. The cold planer also includes a timer. The rotor speed control switch is a toggle switch having an off position, an on position and a neutral position. The rotor speed control switch is able to access a plurality of different engine speeds by toggling the rotor speed control switch repeatedly to the on position.
The controller is programmed to adjust the engine speed to a first speed when the engine is running and the rotor speed control switch is switched to the on position and the clutch is not engaged with the rotor. The controller is also programmed to send a signal to the clutch to engage the rotor when the engine reaches the first speed.
The controller is also programmed to adjust the engine speed from the first speed to the second speed that is higher than the first speed when the engine is running at the first speed and after the controller has sent a signal to the clutch causing the clutch to engage the rotor.
The controller is also programmed to adjust the engine speed from the second speed to a third speed that is higher than the second speed when the rotor speed control switch is toggled to the on position when the engine is running at the second speed.
The first speed is a low idle speed for engaging the clutch. The second speed is a elevated idle speed while the clutch is engaged. The third speed is a low cutting speed. The rotor speed control switch also providing access to higher cutting speeds than the third speed, such as a fourth speed and optionally, a fifth speed. Higher speeds are also possible. In an embodiment, the third speed may range from about 1500 to about 1800 rpm; the fourth speed may range from about 1650 to about 1950 rpm; and the fifth speed may range from about 1800 to about 2100 rpm.
Upon activation of one or more operator inputs selected from the group consisting of activating propel enable switch, changing a height of a cold planer above a work surface, changing a setting of a grade/slope system, stopping the cold planer and combinations thereof, the timer is activated. If a predetermined time period has elapsed without movement of the cold planer after the timer is activated, the controller is programmed to return the engine to the second speed.
A cold planer 10 is illustrated in
A rotor 21 is rotatably mounted to the frame 12 and has a housing 22 surrounding all but the body of the rotor 21, which is necessarily exposed to the road surface 24. The depth of the cut or penetration of the cutting teeth (not shown) of the rotor 12 is controlled by appropriate extension or retraction of the adjustable struts 18, 20 and cylinders 19, 23. The cold planer 10 also includes an engine 26 as a source of power that may drive the rotor 21 via a mechanical drive arrangement that includes pulleys 28, 30, a belt 32 and a belt tensioner 34. Of course, as will be apparent to those skilled in the art, other arrangements can be employed besides the mechanical arrangement shown in
The cold planer 10 also includes a pickup conveyor belt 36 which delivers debris to the discharge conveyor belt 38. The discharge conveyor belt 38 and its associated framing and pulleys (not shown) is supported by the telescoping arm 40. Finally, the cold planer 10 also includes a control console 42.
A control console 42 is partially illustrated in
Still referring to
The rotor speed control switch 58 may be a two position rocker or toggle switch that the operator may use to select from a plurality of different engine/rotor speeds. In one embodiment, the rotor speed control switch 58 enables the operator to choose between three different cutting speeds S3, S4 and S5 and the controller 44 will automatically cause the engine 26 to run at one of the idle speeds S1 and S2, which will be explained in detail below. The selected or desired speed is shown on the display 59, which may be an LED display or other suitable display or indicator.
The propel enable switch 60 may be in the form of a simple push button (see
The grade/slope system is designed to raise and/or lower the struts 18, 20 (
Similarly, in preparing to road the cold planer 10, if the operator lowers the cold planer 10 by changing the manual height adjustment mechanism 66, the controller 44 may also activate the timer 48 for the predetermined time period, such as 10 seconds. If movement of the cold planer 10 is not sensed by the movement sensor 56 or the controller 44 within the predetermined time period, the controller 44 may send a signal to the engine 26 causing the engine 26 to operate at the elevated idle speed S2. Otherwise, the operator can press the propel enable button 60 which will cause the controller 44 to run the engine at S3 or the last operating speed S3, S4 or S5. There is no separate milling and travel modes. Both milling operations and travel or roading operations may be carried out using the same algorithms as shown in
S1, the low idle speed, and S2, the elevated idle speed, are selected based upon the specific cold planer 10 design and the size of the engine 26. By way of example only, one suitable engine speed for the low idle S1 may be 1000 rpm, although S1 may vary from about 800 to about 1100 rpm, and S2 is greater than or equal to S1. S2 may therefore vary from about 800 to about 1350 rpm. One suitable engine speed for the elevated idle S2 may be 1150 rpm. Of course, these values may vary greatly depending upon the size of the engine 26 and the size and type of the cold planer 10.
Once the engine speed is set at S2, a variety of different operator inputs may cause the controller 44 to activate the timer 48 for the predetermined time period, e.g., about 10 seconds, and to set the engine speed to the last operating speed before the rotor speed control switch 58 is turned off. The purpose of the timer 48 is to ensure that the cold planer 10 begins to move after one of the operator inputs is received. Specifically, after the engine speed is raised to S2 at 106, 107, the controller will check to determine whether the propel enable switch 60 is on at 108. Once the propel enable switch 60 is turned to the on position (see
If the grade/slope system is set to auto by way of the switch 62 on the control console 42 at 117, the controller 44 starts the timer at 118 and checks for movement at 119. If no movement is detected by the end of the predetermined time period at 120, the controller 44 reverts the system back to 106 and resets the engine speed at S2. Similarly, if the grade/slope setting is changed by way of the controlled mechanism 64 on the control console 42 at 121, the timer is started at 122 and the controller 44 checks for movement of the cold planer 10 at 123. If no movement is detected by the end of the elapsed time period at 124, the system reverts back to step 106 and the speed of the engine 26 is reset to S2. Also, if the operator stops the cold planer 10 or for another reason, the cold planer 10 is stopped or its motion is ceased at 125, the timer is started at 126 and the controller 44 checks for movement at 127. If no movement is detected after the predetermined time period has elapsed at 128, the controller sends a signal to the engine to revert to the elevated idle speed S2, or the system returns to step 106 as shown.
The operator is free to use the rotor speed control switch 60 to change the engine speed at any time. The speed chosen by the operator is shown on the display 60 and the engine 26 will operate at that speed after the propel enable switch is pressed at 108, the cold planer 10 is lowered at 112, the grade/slope auto/manual switch 62 is switched from manual to auto mode, the grade/slope value is adjusted via the grade/slope mechanism 64 while the grade/slope auto/manual switch is in auto mode, or when the cold planer 10 is manually lowered, e.g., by lowering the cold planer 10 using the height adjustment mechanism 66.
Still referring to
It will be noted that speed control for milling operations is the same as for roading or travel operations. That is, there is no separate travel and milling modes. To travel, the operator merely raises the cold planer 10 to a suitable height using the height adjust knob 66 followed by pressing or activating the propel enable switch 60, which will cause the controller 44 to run the engine 26 at S3 or the last operating speed S3, S4 or S5.
Of course, the variables discussed above may be changed based upon machine requirements. The purpose of the described control system is two-fold. First, cold planers 10 can consume large quantities of fuel and reducing the speed of the engine 26 between movements of the cold planer 10, especially if the delay between movements is greater than a predetermined time period, e.g. 5 seconds, 6 seconds, 10 seconds, 20 seconds, 30 seconds, etc., fuel is saved by lowering the engine speed to the elevated idle speed S2 without substantially compromising the speed of the milling operation. S2 is greater than or equal to S1, which may be the lowest operating speed of the engine 26. The operator can then reestablish the desired operating speed, S3, S4 or S5, by pressing the rotor speed control switch 58 the desired number of times.
The second benefit provided by the disclosed control system is saving wear and tear on the clutch 50. Specifically, the clutch 50 remains engaged with the rotor 21 while the engine 26 is operating at the elevated idle speed S2. The reader will note that if no movement of the cold planer 10 is detected after a predetermined time period following five different operator input actions shown at 108, 112, 117, 121 and 125, the speed of the engine 26 is lower to the elevated idle speed S2. Thus, the clutch 50 remains engaged with the rotor 21. Disengagement of the clutch only comes after a complete shut down, upon initiation by the operator.
A third benefit is the use of a single control mode for both milling and travel operations. The operator does not need to know or remember what mode he/she is in. There is preferably only a single speed control that is used for milling and roading.
Further, it will be noted that the number of operating speeds in the above example is just three, S3, S4 and S5. However, the number of operating speed may vary greatly, depending upon the machine and working conditions. For example, anywhere from two to eight different operating speeds may also be desirable.
In operation, the operator will engage the rotor 21 by pressing the rotor speed control switch 58 on the control console 42. The rotor speed control switch 58 may be a momentary two position switch, a rocker switch or a toggle switch, and the default position may be a center position of the switch 58 as illustrated in
The rotor 21 is engaged by pressing the rotor speed control switch 58 in the on direction as illustrated in
The operator will be able to select between a plurality of milling speeds S3, S4, S5. For at least some cold planers, suitable low, medium and high milling speeds of 1500-1800 rpm (e.g., 1600 rpm), 1650-1950 rpm (e.g., 1750 rpm) and 1800-2100 rpm (e.g., 1900 rpm) will be satisfactory. The number of different cutting/milling speeds and the actual engine speeds used for the cutting/milling will vary from cold planer to cold planer as will be apparent to those skilled in the art. The speed of the engine 26 is selected by pressing the rotor speed control switch 58 in the on/cycle direction once for S3, twice for S4 and three times for S5 as generally illustrated in
The speed of the engine 26 will elevate to the desired setting once the speed of the engine 26 reaches the elevated idle speed S2. After the engine 26 reaches the speed S2 or a higher speed, a plurality of operator inputs can initiate the activation of the timer 48 so the controller 44 can determine that the cold planer 10 is indeed moving within the predetermined time period. As explained above, the predetermined time period can be relatively short, such as five, six or 10 seconds long or may be extended to a longer time period such as 15 or 20 seconds or longer. Ten seconds has proven to be a satisfactory time period for at least some embodiments. However, the predetermined time period may range from about 5 to about 25 seconds, more typically, from about 5 to about 15 seconds.
For example, when the propel enable switch 60 is pressed to the on position, the operator has the predetermined time period within which to start moving the cold planer 10. If movement is not detected by the controller 44 within the predetermined time period, the speed of the engine 26 is reduced to S2. The operator will have to press the propel enable switch 60 again to re-enable movement of the cold planer 10.
If the operator adjusts height of the cold planer 10, via the height adjustment mechanism 66, the timer is started and if movement is not initiated before the end of the predetermined time period, the controller 44 sends a signal to the engine 26 to lower the engine speed to S2. Similarly, if the grade and slope system is set to auto mode via the switch 62, the timer will start and the operator has the predetermined time period within which to start movement of the cold planer 10 or the controller 44 will send a signal to the engine 26 to reduce the engine speed to S2. Further, if a setting in the grade and slope system is changed, such as a manual adjustment via the grade/slope manual slope manual adjustment mechanism 64, the timer 48 will be activated and the operator has the predetermined time period within which to initiate movement of the cold planer 10. Also, if the operator stops the cold planer 10 or if the cold planer 10 stops for some other reason, the timer 48 will be activated and the controller will communicate with the engine to reduce the engine speed to S2 if movement is not reinitiated within the predetermined time period.
Essentially, any time a new command is given, the timer 48 will be activated. When the cold planer 10 is propelling forward with the rotor 21 activated, it is assumed that the cold planer 10 is milling (although in some instances it may not be) and the speed of the engine 26 will remain at the desired speed, S3, S4, S5 . . . The timer 48 need not be activated when the cold planer 10 is moving.
A benefit of automatically lowering the speed of the engine 26 is reduced fuel consumption and reduced noise levels. The timer 48 effectively limits the cycling from the elevated idle speed S2 to the higher S3, S4 or S5 milling speeds. If the desired cutting speed is changed while the speed of the engine 26 is elevated, i.e. before the timer expires or while propelling forward with the rotor 21 activated, the actual desired speed may change to the new setting immediately. When the cold planer 10 is propelling in a reverse direction, it may be assumed that a cold planer 10 is not milling and the speed of the engine 26 will follow the desired speed based upon the propel system engine speed map, not the set S3, S4 or S5 milling speed.
To turn the rotor off, the operator will press the rotor speed control switch 58 in the off direction. The clutch 50 will automatically disengage from the rotor 21 and the speed of the engine 26 may drop to the S1 speed or a lower speed. For example, the engine speed may drop to 800 rpm or the lowest engine speed based upon the other machine commands being performed. In an embodiment, S1 may be the lowest engine speed.
