Method And Apparatus For Automating Power Take-Offs For Vehicles and Equipment

Abstract

A system and method of this disclosure control an on/off state of a power take-off by monitoring the power demand of a fluid power circuit that includes the power take-off and a piece of equipment connected to the power take-off. The power demand may be indicated by a pressure or temperature of a fluid power circuit, by a motion of the equipment or its hand-held controller, or by an engine torque of an engine driving the power take-off. When the equipment transitions between an off state and an on state, the controller automatically engages the power take-off. When the equipment is in the on-state for a predetermined amount of time and the power demand is at or below a predetermined threshold during the predetermined amount of timethereby indicating idle time or an inactive state of the equipmentthe controller automatically disengages the power take-off.

Claims

1. A system configured for control of a power take-off connected to an engine of a motor vehicle and a piece of equipment, the system comprising: a sensor arranged to monitor a power demand of the piece of equipment; a controller including a microprocessor and associated software in circuit communication with the sensor and the power take-off; wherein when the piece of equipment transitions between an off state and an on state, the controller automatically engages the power take-off; and wherein when the piece of equipment is in the on-state for a predetermined amount of time and the power demand as indicated by the sensor is at or below a predetermined threshold during the predetermined amount of time, the controller automatically disengages the power take-off; and wherein the predetermined threshold indicates an inactive state of the piece of equipment.

2. The system of claim 1, further comprising a fluid power circuit in communication with the sensor, the power take-off, and the piece of equipment.

3. The system of claim 1, wherein the sensor is configured to sense a fluid pressure, a fluid temperature, or the fluid pressure and temperature of the fluid power circuit.

4. The system of claim 1, wherein the sensor is an accelerometer.

5. The system of claim 4, further comprising, the accelerometer is connected to a remote command configured to control the piece of equipment.

6. The system of claim 4, further comprising, the accelerometer is connected to the piece of equipment.

7. The system of claim 1, wherein the sensor is a torque sensor configured to detect a torque of the engine of the motor vehicle.

8. The system of claim 1, wherein the sensor is configured as a switch.

9. The system of claim 1, wherein the piece of equipment is an air compressor.

10. The system of claim 1, wherein the piece of equipment is a crane.

11. A method for automatically engaging and disengaging a power take-off connected to an engine of a motor vehicle and a piece of equipment, the power take-off in communication with a sensor arranged to monitor a power demand of the piece of equipment method and a controller including a microprocessor and associated software in circuit communication with the sensor and the power take-off, the method comprising the controller: monitoring a power demand of the piece of equipment as indicated by the sensor; automatically engaging the power take-off when the piece of equipment transitions between an off state and an on state; and automatically disengaging the power take-off when the piece of equipment is in the on-state for a predetermined amount of time and the power demand as indicated by the sensor is at or below a predetermined threshold during the predetermined amount of time; wherein the predetermined threshold indicates an inactive state of the piece of equipment.

12. The method of claim 11, wherein, a fluid power circuit is in communication with the sensor, the power take-off, and the piece of equipment.

13. The method of claim 12, wherein the sensor is configured to sense a fluid pressure, a fluid temperature, or the fluid pressure and temperature of the fluid power circuit.

14. The method of claim 11, wherein the sensor is an accelerometer.

15. The system of claim 14, wherein the accelerometer is connected to a remote command configured to control the piece of equipment.

16. The method of claim 14, wherein the accelerometer is connected to the piece of equipment.

17. The method of claim 11, wherein the sensor is a torque sensor configured to detect a torque of the engine of the motor vehicle.

18. The method of claim 11, wherein the sensor is configured as a switch.

19. The method of claim 11, wherein the piece of equipment is an air compressor.

20. The method of claim 11, wherein the piece of equipment is a crane.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a flow chart of an embodiment of an automatic on/off system for a power take-off (PTO). The PTO may time out after a predetermined amount of inactive time. By way of a non-limiting example, the predetermined amount of inactive time may be 15 minutes.

[0011] FIG. 2 is a schematic illustrating an embodiment of a PTO on/off system of FIG. 1 in circuit relationship to a hydraulic pump providing fluid to equipment including a crane, outrigger, and air compressor. In embodiments, a pressure sensor or switch may be included in the fluid circuit and connected to the PTO control.

[0012] FIG. 3 is an embodiment of a graphical user interface of this disclosure.

[0013] FIG. 4 is another view of the graphical user interface of FIG. 3 located in a cab of the motor vehicle. The graphical user interface may also be located outside of the cab.

[0014] FIG. 5 is a state diagram of an embodiment of a control system and method of this disclosure. The power demand of the equipment, which may be indicated by hydraulic power or pneumatic power, may be monitored by a sensor or switch configured to detect pressure or temperature of the fluid circuit. In some embodiments, the power demand may be monitored by a sensor or switch configured to detect motion of the equipment or its remote command, or may be configured to detect engine torque.

DETAILED DESCRIPTION

[0015] Referring to the drawings, embodiments of a system and method 10 of this disclosure are configured for control of a power take-off (PTO) connected to an engine of a motor vehicle and at least one piece of equipment. The system and method 10 includes a sensor or switch 40 arranged to directly or indirectly monitor a power demand of the piece of equipment and a controller 20 including a microprocessor and associated software in circuit communication with the sensor or switch 40 and the PTO. The sensor or switch 40 may be configured to detect pressure or temperature of a fluid circuit 30, a motion of the equipment or a remote command associated with the equipment, or engine torque of the motor vehicle engine connected to the PTO.

[0016] In embodiments, the PTO control system and method 10 queries only one sensed input to decide whether to disengage the PTO. Engine speed is not monitored. When the at least one piece of equipment transitions between an off state and an on state, the controller 20 automatically engages the power take-off and when the at least one piece of equipment is in the on-state for a predetermined amount of time and power demand as sensed by the sensor 40 is at or below a predetermined threshold during the predetermined amount of time, the controller 20 automatically disengages the power take-off. The system and method 10 may continue engagement as the power demand remains above the predetermined threshold. The at least one piece of equipment may be an air compressor. In other embodiments, the equipment is a crane.

[0017] Some embodiments of this disclosure include a PTO control system and method 10 that senses a pressure of a fluid power system 30 connected to a piece of equipment initially enabled by an operator and, based upon the sensed pressure, automatically engages and disengages the PTO. The fluid power system 30 may be a hydraulic system or a pneumatic system. The control system and method 10 may disengage the PTO after the sensed pressure remains below a threshold pressure indicative of no demand or no load on the piece of equipment or fluid power system 30 for a predetermined amount of time. In some embodiments, the equipment may include a crane and an air compressor and PTO engagement and disengagement may be a function of demand for compressed air. Regardless of the equipment, the automatic engagement and disengagement allows the engine to idle-down or stop, thereby saving fuel and reducing noise and heat of the fluid power system 30.

[0018] By way of a non-limiting example, a motorized vehicle may include a PTO in communication with a hydraulic pump or motor providing hydraulic fluid to a crane, tool circuit, and an air compressor. Each fluid line may include a pressure sensor or switch to monitor a fluid pressure. The fluid pressure may be proportionate to a load on the equipment, with a predetermined pressure indicative of no load on a respective piece of equipment. A PTO control 20 of this disclosure may reside between the vehicle power control and the PTO and includes a microprocessor with associated software.

[0019] The PTO control 20 may also include a graphical user interface located in a cab of the motor vehicle, on or in a work box or cabinet of the motor vehicle, or both in the cab and the cabinet. The user interface may also provide on-off control of the crane, tool circuit, and air compressor.

[0020] One of the pressure sensors or switches 40 used by the PTO control 20 may be the same sensor or switch connected to a clutch of the pump or motor providing the hydraulic fluid. An operator may manually or remotely engage the crane or compressor switch, thereby enabling the PTO. The control system and method 10 automatically engages the PTO and then monitors, for example, crane demand and compressor demand to decide when to disengage the PTO. In some embodiments, the PTO may time out after a predetermined amount of inactive time. Inactive time is a period of time when, for example, a pressure of the fluid power circuit 30 is at or below a predetermined pressure, thereby indicating inactivity of the equipment. The amount of inactive time may be any time preferable or suitable, for example, 5 minutes, 10 minutes, 15 minutes.

[0021] Other embodiments of this disclosure include a PTO control system and method 10 that senses motion of a remote command such as a switch or joystick connected to a piece of equipment initially enabled by an operator and, based upon the sensed motion of the remote command, automatically engages and disengages the PTO. When the at least one piece of equipment transitions between an off state and an on state, the controller 20 automatically engages the power take-off and when the at least one piece of equipment is in the on-state for a predetermined amount of time and the remote command or equipment is idle during the predetermined amount of time (i.e, not moving), the controller 20 automatically disengages the PTO. Inactive time is a period of time when the status of the remote command is idle, thereby indicating inactivity of the equipment. The amount of inactive time may be any time preferable or suitable, for example, 5 minutes, 10 minutes, 15 minutes.

[0022] Another embodiment of this disclosure includes a PTO control system and method 10 that senses velocity or acceleration of a piece of equipment initially enabled by an operator and, based upon the sensed velocity or acceleration, automatically engages and disengages the PTO. The system may include a sensor 40 such as an accelerometer arranged to monitor movement of the at least one piece of equipment. When the at least one piece of equipment transitions between an off state and an on state, the microprocessor automatically engages the PTO and when the at least one piece of equipment is in the on-state for a predetermined amount of time and movement is at or below a predetermined velocity or acceleration during the predetermined amount of time, the microprocessor automatically disengages the PTO. Inactive time is a period of time when the velocity or acceleration is at or below a predetermined threshold , thereby indicating inactivity of the equipment. The amount of inactive time may be any time preferable or suitable, for example, 5 minutes, 10 minutes, 15 minutes.

[0023] In still other embodiments, the PTO control system and method 10 may be configured to determine whether to automatically turn-on/off the PTO on the basis of engine torque. The system and method 10 may include a sensor 40 arranged to monitor torque of an engine associated with the at least one piece of equipment. When the at least one piece of equipment transitions between an off state and an on state, the controller 20 automatically engages the PTO and when the at least one piece of equipment is in the on-state for a predetermined amount of time and engine torque is at or below a predetermined velocity or acceleration during the predetermined amount of time, the controller automatically disengages the power take-off. Inactive time is a period of time when the engine torque is at or below a predetermined threshold, thereby indicating inactivity of the equipment. The amount of inactive time may be any time preferable or suitable, for example, 5 minutes, 10 minutes, 15 minutes.

[0024] While embodiments of a PTO control system and method have been described, modifications may be made by persons of ordinary skill in the field without departing from the scope of the following claims. The elements recited in the claims are entitled to their full range of equivalents.