Differential lock control system for agricultural vehicles
First Claim
1. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting power from the engine to the driven wheels and permitting relative velocity between the driven wheels and a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals, a control system comprising:
- a vehicle velocity sensor configured to detect a parameter related to the ground velocity of the vehicle and to generate a vehicle velocity signal representative thereof;
a wheel velocity sensor configured to detect the velocity of at least one of the driven wheels and to generate a wheel velocity signal representative thereof;
a comparator circuit coupled to the vehicle velocity sensor and to the wheel velocity sensor and configured to compare the vehicle velocity signal and the wheel velocity signal and to generate a slip signal representative of the degree of slip of the driven wheel; and
a control circuit coupled to the comparator circuit and to the differential locking mechanism and configured to generate control signals when a predetermined degree of slip occurs and to apply the control signals to the differential locking mechanism to limit relative velocity between the driven wheels.
3 Assignments
0 Petitions
Accused Products
Abstract
A control system for engaging, disengaging and re-engaging a differential locking mechanism in an agricultural vehicle includes a control circuit configured to receive signals representative of vehicle operating parameters and to generate control signals corresponding to the desired state (i.e. engaged or disengaged) of a differential locking mechanism for limiting relative velocity between two driven wheels. Sensors are associated with the rear wheels, rear service brakes, implement positioning circuit, the vehicle body and the front axle to provide parameter signals related to wheel speed, braking, implement position and vehicle speed. Control logic executed by the control circuit in a continuously cycled routine determines the desired state of the differential locking mechanism based upon the operating parameters. The control circuit applies an appropriate control signal to the differential locking mechanism causing engagement or disengagement in accordance with the desired state.
88 Citations
32 Claims
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1. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting power from the engine to the driven wheels and permitting relative velocity between the driven wheels and a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals, a control system comprising:
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a vehicle velocity sensor configured to detect a parameter related to the ground velocity of the vehicle and to generate a vehicle velocity signal representative thereof; a wheel velocity sensor configured to detect the velocity of at least one of the driven wheels and to generate a wheel velocity signal representative thereof; a comparator circuit coupled to the vehicle velocity sensor and to the wheel velocity sensor and configured to compare the vehicle velocity signal and the wheel velocity signal and to generate a slip signal representative of the degree of slip of the driven wheel; and a control circuit coupled to the comparator circuit and to the differential locking mechanism and configured to generate control signals when a predetermined degree of slip occurs and to apply the control signals to the differential locking mechanism to limit relative velocity between the driven wheels. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism engageable to limit the relative velocity between the driven wheels in response to control signals and a brake coupled to each driven wheel, a control system comprising:
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a brake detecting circuit coupled to the brakes and configured to generate a braking signal upon application of a brake; and a control circuit coupled to the brake detecting circuit and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to selectively engage, disengage and re-engage the mechanism in response to the braking signal. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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18. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals and an implement positioning system for raising and lowering an implement coupled to the vehicle, a control system comprising:
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an implement position detecting circuit coupled to the implement positioning system and configured to generate an implement position signal representative of the implement position; and a control circuit coupled to the implement position detecting circuit and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to engage the differential locking mechanism when the implement is in a first position and to disengage the mechanism when the implement is in a second position. - View Dependent Claims (19, 20, 21, 22, 23, 24, 25, 26)
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27. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, a differential locking mechanism for limiting the relative velocity between the driven wheels in response to control signals, a control system comprising:
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a ground speed sensor configured to detect a parameter proportional to the ground speed of the vehicle and to generate speed signals representative thereof; and a control circuit coupled to the ground speed sensor and to the differential locking mechanism and configured to generate control signals and to apply the control signals to the differential locking mechanism to engage the differential locking mechanism when the vehicle ground speed falls below a predetermined speed, to disengage the mechanism when the vehicle ground speed exceeds the predetermined speed and to re-engage the mechanism when the vehicle ground speed again falls below the predetermined speed. - View Dependent Claims (28, 29)
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30. In an agricultural vehicle having an engine, at least two driven wheels, a differential for transmitting rotary motion from the engine to the driven wheels and permitting relative velocity between the driven wheels, differential locking means engageable for limiting the relative velocity between the driven wheels in response to control signals, a brake associated with each of the driven wheels and means for positioning an implement, a control system comprising:
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first sensing means for sensing a first operating parameter of the vehicle and for producing a first parameter signal representative thereof; second sensing means for sensing a second operating parameter of the vehicle and for producing a second parameter signal representative thereof; third sensing means for sensing a third operating parameter of the vehicle and for producing a third operating parameter signal representative thereof; and a control circuit coupled to the first sensing means, the second sensing means, the third sensing means and the differential locking means and configured to generate control signals for selectively engaging the differential locking means in response to the first parameter signal, the second parameter signal and the third parameter signal. - View Dependent Claims (31, 32)
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Specification